NCBI Conserved Domain Search

Immunoglobulin (Ig)-like domain of human neurofascin (NF); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of human neurofascin (NF). NF belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region, and a cytoplasmic domain. NF has many alternatively spliced isoforms having different temporal expression patterns during development. NF participates in axon subcellular targeting and synapse formation, however little is known of the functions of the different isoforms. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lacks a C" strand.

Pssm-ID: 409459 Cd Length: 95 Bit Score: 212.14 E-value: 3.75e-64

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  118 PTITKQSAKDHIVDPRDNILIECEAKGNPAPSFHWTRNSRFFNIAKDPRVSMRRRSGTLVIDFRSGGRPEEYEGEYQCFA 197
Cdd:cd05875      1 PTITKQSAKDYIVDPRDNILIECEAKGNPVPTFHWTRNGKFFNVAKDPRVSMRRRSGTLVIDFRGGGRPEDYEGEYQCFA 80

                           90
                   ....*....|....*
gi 2217265341  198 RNKFGTALSNRIRLQ 212
Cdd:cd05875     81 RNKFGTALSNKIRLQ 95

Immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM) and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains NrCAM [Ng(neuronglia)CAM-related cell adhesion molecule], which is primarily expressed in the nervous system, and human neurofascin. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lacks a C" strand.

Pssm-ID: 409396 [Multi-domain] Cd Length: 94 Bit Score: 184.15 E-value: 1.99e-54

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  118 PTITKQSAKDHIVDPRDNILIECEAKGNPAPSFHWTRNSRFFNIAKDPRVSMRRRSGTLVIDFRSGGrPEEYEGEYQCFA 197
Cdd:cd05733      1 PTITEQSPKDYIVDPRDNITIKCEAKGNPQPTFRWTKDGKFFDPAKDPRVSMRRRSGTLVIDNHNGG-PEDYQGEYQCYA 79

                           90
                   ....*....|....*
gi 2217265341  198 RNKFGTALSNRIRLQ 212
Cdd:cd05733     80 SNELGTAISNEIRLV 94

Second immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM), and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM) and similar proteins. L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains, five fibronectin type III domains, a transmembrane region, and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1 that involves abnormalities of axonal growth. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409432 Cd Length: 91 Bit Score: 178.07 E-value: 2.48e-52

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  221 KENLDPVVVQEGAPLTLQCNPPPGLPSPVIFWMSSSMEPITQDKRVSQGHNGDLYFSNVMLQDMQTDYSCNARFHFTHTI 300
Cdd:cd05845      1 KEKIDPVEVEEGDPVVLPCNPPKGAPPPRIYWMNSSLEHITQDERVSMGQNGDLYFSNVMEQDSHPDYICHAHFPGTRTI 80

                           90
                   ....*....|.
gi 2217265341  301 QQKNPFTLKVL 311
Cdd:cd05845     81 VQKEPITLKVL 91

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM), and similar domains; The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM and human neurofascin.

Pssm-ID: 409394 [Multi-domain] Cd Length: 83 Bit Score: 167.97 E-value: 8.60e-49

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  329 TASSQMVLRGMDLLLECIASGVPTPDIAWYKKGGDLPSDKAKFENFNKALRITNVSEEDSGEYFCLASNKMGSIRHTISV 408
Cdd:cd05731      1 SESSTMVLRGGVLLLECIAEGLPTPDIRWIKLGGELPKGRTKFENFNKTLKIENVSEADSGEYQCTASNTMGSARHTISV 80


                   ...
gi 2217265341  409 RVK 411
Cdd:cd05731     81 TVE 83

Fourth immunoglobulin (Ig)-like domain of NrCAM (NgCAM-related cell adhesion molecule); The members here are composed of the fourth immunoglobulin (Ig)-like domain of NrCAM (NgCAM-related cell adhesion molecule). NrCAM belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six IG-like domains and five fibronectin type III domains, a transmembrane region, and an intracellular domain. NrCAM is primarily expressed in the nervous system.

Pssm-ID: 409454 Cd Length: 89 Bit Score: 148.98 E-value: 3.96e-42

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  415 YWLDEPKNLILAPGEDGRLVCRANGNPKPTVQWMVNGEPLQSAPPNPNREVAGDTIIFRDTQISSRAVYQCNTSNEHGYL 494
Cdd:cd05868      1 YWITAPTNLVLSPGEDGTLICRANGNPKPSISWLTNGVPIEIAPTDPSRKVDGDTIIFSKVQERSSAVYQCNASNEYGYL 80


                   ....*....
gi 2217265341  495 LANAFVSVL 503
Cdd:cd05868     81 LANAFVNVL 89

Immunoglobulin (Ig)-like domain of NrCAM (Ng (neuronglia) CAM-related cell adhesion molecule); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of NrCAM (Ng (neuronglia) CAM-related cell adhesion molecule). NrCAM belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region, and an intracellular domain. NrCAM is primarily expressed in the nervous system.

Pssm-ID: 409458 Cd Length: 95 Bit Score: 143.20 E-value: 5.47e-40

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  118 PTITKQSAKDHIVDPRDNILIECEAKGNPAPSFHWTRNSRFFNIAKDPRVSMRRRSGTLVIDFRSGGRPEEYEGEYQCFA 197
Cdd:cd05874      1 PTITHQSPKDYIVDPRENIVIQCEAKGKPPPSFSWTRNGTHFDIDKDPKVTMKPNTGTLVINIMNGEKAEAYEGVYQCTA 80

                           90
                   ....*....|..
gi 2217265341  198 RNKFGTALSNRI 209
Cdd:cd05874     81 RNERGAAVSNNI 92

Fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related); The members here are composed of the fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related). These proteins belong to the L1 subfamily of cell adhesion molecules (CAMs) and are comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. These molecules are primarily expressed in the nervous system. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth.

Pssm-ID: 409367 [Multi-domain] Cd Length: 89 Bit Score: 134.88 E-value: 3.11e-37

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  415 YWLDEPKNLILAPGEDGRLVCRANGNPKPTVQWMVNGEPLQSAPPNPNREVAGDTIIFRDTQISSRAVYQCNTSNEHGYL 494
Cdd:cd04978      1 YWIIEPPSLVLSPGETGELICEAEGNPQPTITWRLNGVPIEPAPEDMRRTVDGRTLIFSNLQPNDTAVYQCNASNVHGYL 80


                   ....*....
gi 2217265341  495 LANAFVSVL 503
Cdd:cd04978     81 LANAFLHVL 89

Bravo-like intracellular region; This is the very C-terminal intracellular region of neural adhesion molecule L1 proteins that are also known as Bravo or NrCAM. It lies upstream of the IG and Fn3 domains and has the highly conserved motif FIGEY. The function is not known.

Pssm-ID: 464016 Cd Length: 88 Bit Score: 132.06 E-value: 3.08e-36

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341 1316 KRSRGGKYPVREKKDVPLGPEDPKEEDGSF-DYSDEDNKPLQGSQTSLDGTIKQQESD--DSLVDYGEGGEGQFNEDGSF 1392
Cdd:pfam13882    1 KRNKGGKYSVKEKEDAHGDPEDQPMDEDAFgEYSDLDEKPLKSSQPSLSSDSKLVDSDstDSLDDYGDGDGGQFNEDGSF 80


                   ....*...
gi 2217265341 1393 IGQYTVKK 1400
Cdd:pfam13882   81 IGQYGGKK 88

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM); The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains, five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM.

Pssm-ID: 409460 [Multi-domain] Cd Length: 83 Bit Score: 100.37 E-value: 4.06e-25

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  331 SSQMVLRGMDLLLECIASGVPTPDIAWYKKGGDLPSDKAKFENFNKALRITNVSEEDSGEYFCLASNKMGSIRHTISVRV 410
Cdd:cd05876      3 SSLVALRGQSLVLECIAEGLPTPTVKWLRPSGPLPPDRVKYQNHNKTLQLLNVGESDDGEYVCLAENSLGSARHAYYVTV 82


                   .
gi 2217265341  411 K 411
Cdd:cd05876     83 E 83

Fourth immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM); The members here are composed of the fourth immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region, and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM.

Pssm-ID: 409453 [Multi-domain] Cd Length: 89 Bit Score: 98.81 E-value: 1.52e-24

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  415 YWLDEPKNLILAPGEDGRLVCRANGNPKPTVQWMVNGEPLQSAPPNPNREVAGDTIIFRDTQISSRAVYQCNTSNEHGYL 494
Cdd:cd05867      1 YWTRRPQSHLYGPGETARLDCQVEGIPTPNITWSINGAPIEGTDPDPRRHVSSGALILTDVQPSDTAVYQCEARNRHGNL 80


                   ....*....
gi 2217265341  495 LANAFVSVL 503
Cdd:cd05867     81 LANAHVHVV 89

Fibronectin type 3 domain; One of three types of internal repeats found in the plasma protein fibronectin. Its tenth fibronectin type III repeat contains an RGD cell recognition sequence in a flexible loop between 2 strands. Approximately 2% of all animal proteins contain the FN3 repeat; including extracellular and intracellular proteins, membrane spanning cytokine receptors, growth hormone receptors, tyrosine phosphatase receptors, and adhesion molecules. FN3-like domains are also found in bacterial glycosyl hydrolases.

Pssm-ID: 238020 [Multi-domain] Cd Length: 93 Bit Score: 78.31 E-value: 2.36e-17

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  705 PDRPRDLELTDLAERSVRLTWIPGDANNSPITDYVVQFEEDqfQPGVWHDHSKYPGSVNSAVLR-LSPYVNYQFRVIAIN 783
Cdd:cd00063      1 PSPPTNLRVTDVTSTSVTLSWTPPEDDGGPITGYVVEYREK--GSGDWKEVEVTPGSETSYTLTgLKPGTEYEFRVRAVN 78

                           90
                   ....*....|..
gi 2217265341  784 EVGSSHPSLPSE 795
Cdd:cd00063     79 GGGESPPSESVT 90

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 77.55 E-value: 4.23e-17

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341   331 SSQMVLRGMDLLLECIASGVPTPDIAWYKKGGDLPSDKAKF----ENFNKALRITNVSEEDSGEYFCLASNKMGSIRHTI 406
Cdd:smart00410    2 PSVTVKEGESVTLSCEASGSPPPEVTWYKQGGKLLAESGRFsvsrSGSTSTLTISNVTPEDSGTYTCAATNSSGSASSGT 81


                    ....
gi 2217265341   407 SVRV 410
Cdd:smart00410   82 TLTV 85

Fourth Ig domain of the neural cell adhesion molecule contactin-2, and similar domains; The members here are composed of the fourth Ig domain of the neural cell adhesion molecule contactin-2. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (also called TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. The first four Ig domains form the intermolecular binding fragment which arranges as a compact U-shaped module by contacts between Ig domains 1 and 4, and domains 2 and 3. It has been proposed that a linear zipper-like array forms, from contactin-2 molecules alternatively provided by the two apposed membranes.

Pssm-ID: 143205 [Multi-domain] Cd Length: 85 Bit Score: 73.79 E-value: 9.76e-16

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  416 WLDEPKNLILAPGEDGRLVCRANGNPKPTVQWMVNGEPLqsapPNPNR-EVAGDTIIFRDTQISSRAVYQCNTSNEHGYL 494
Cdd:cd05728      2 WLKVISDTEADIGSSLRWECKASGNPRPAYRWLKNGQPL----ASENRiEVEAGDLRITKLSLSDSGMYQCVAENKHGTI 77


                   ....*...
gi 2217265341  495 LANAFVSV 502
Cdd:cd05728     78 YASAELAV 85

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 72.68 E-value: 2.66e-15

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  605 PEDQVARRGTTVQLECRVKHDPslKLTVSWLKDDEPLYIGNR--MKKEDD--SLTIFGVAERDQGSYTCVASTELDQDLA 680
Cdd:pfam07679    7 PKDVEVQEGESARFTCTVTGTP--DPEVSWFKDGQPLRSSDRfkVTYEGGtyTLTISNVQPDDSGKYTCVATNSAGEAEA 84


                   ....*.
gi 2217265341  681 KAYLTV 686
Cdd:pfam07679   85 SAELTV 90

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

Pssm-ID: 409544 [Multi-domain] Cd Length: 87 Bit Score: 72.53 E-value: 2.86e-15

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2217265341  527 LDCPFFGSPIPTLRWFKngQGSNLDGGNYHVY--ENGSLEIKMIRKEDQGIYTCVATNILGKAENQVRLEV 595
Cdd:cd20952     19 LNCQATGEPVPTISWLK--DGVPLLGKDERITtlENGSLQIKGAEKSDTGEYTCVALNLSGEATWSAVLDV 87

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 70.36 E-value: 1.39e-14

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217265341  338 GMDLLLECIASGVPTPDIAWYKKGGDLPSD---KAKFENFNKALRITNVSEEDSGEYFCLASNKMGSIRHTISVRV 410
Cdd:pfam07679   15 GESARFTCTVTGTPDPEVSWFKDGQPLRSSdrfKVTYEGGTYTLTISNVQPDDSGKYTCVATNSAGEAEASAELTV 90

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 69.90 E-value: 1.79e-14

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  331 SSQMVLRGMDLLLECIASGVPTPDIAWYKKGG---DLPSDKAKFENFNKALRITNVSEEDSGEYFCLASN 397
Cdd:pfam13927    9 SSVTVREGETVTLTCEATGSPPPTITWYKNGEpisSGSTRSRSLSGSNSTLTISNVTRSDAGTYTCVASN 78

Fibronectin type III domain;

Pssm-ID: 394996 [Multi-domain] Cd Length: 85 Bit Score: 68.21 E-value: 7.93e-14

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  706 DRPRDLELTDLAERSVRLTWIPGDANNSPITDYVVQFEEDQfQPGVWHdHSKYPGSVNSAVLR-LSPYVNYQFRVIAINE 784
Cdd:pfam00041    1 SAPSNLTVTDVTSTSLTVSWTPPPDGNGPITGYEVEYRPKN-SGEPWN-EITVPGTTTSVTLTgLKPGTEYEVRVQAVNG 78


                   ....*..
gi 2217265341  785 VGSSHPS 791
Cdd:pfam00041   79 GGEGPPS 85

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409570 [Multi-domain] Cd Length: 88 Bit Score: 65.49 E-value: 8.41e-13

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  414 PYWLDEP-KNLILAPGEDGRLVCRANGNPKPTVQWMVNGEPLQSAPPNPNREVAGDTIIfrDTQISSRAVYQCNTSNEHG 492
Cdd:cd20978      1 PKFIQKPeKNVVVKGGQDVTLPCQVTGVPQPKITWLHNGKPLQGPMERATVEDGTLTII--NVQPEDTGYYGCVATNEIG 78

                           90
                   ....*....|
gi 2217265341  493 YLLANAFVSV 502
Cdd:cd20978     79 DIYTETLLHV 88

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 64.66 E-value: 9.25e-13

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217265341  341 LLLECIASGVPTPDIAWYKKGGDLPSDKA---KFENFNKALRITNVSEEDSGEYFCLASNKMGSIRHTI 406
Cdd:cd00096      1 VTLTCSASGNPPPTITWYKNGKPLPPSSRdsrRSELGNGTLTISNVTLEDSGTYTCVASNSAGGSASAS 69

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 64.59 E-value: 1.57e-12

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217265341  526 RLDCPFFGSPIPTLRWFKNGQGSNlDGGNYHVYENG---SLEIKMIRKEDQGIYTCVATNILGKAENQVRLEV 595
Cdd:pfam07679   19 RFTCTVTGTPDPEVSWFKDGQPLR-SSDRFKVTYEGgtyTLTISNVQPDDSGKYTCVATNSAGEAEASAELTV 90

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 64.06 E-value: 1.90e-12

                            10        20        30        40        50        60        70
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217265341   526 RLDCPFFGSPIPTLRWFKNGQGSNLDGGNYHVYENG---SLEIKMIRKEDQGIYTCVATNILGKAENQVRLEV 595
Cdd:smart00410   13 TLSCEASGSPPPEVTWYKQGGKLLAESGRFSVSRSGstsTLTISNVTPEDSGTYTCAATNSSGSASSGTTLTV 85

Third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409390 [Multi-domain] Cd Length: 83 Bit Score: 63.95 E-value: 1.99e-12

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  512 PRNQlirVILYNRT-RLDCPFFGSPIPTLRWFKNGqgSNLDGGNYHVYENGSLEIKMIRKEDQGIYTCVATNILGKAENQ 590
Cdd:cd05725      4 PQNQ---VVLVDDSaEFQCEVGGDPVPTVRWRKED--GELPKGRYEILDDHSLKIRKVTAGDMGSYTCVAENMVGKIEAS 78


                   ....*
gi 2217265341  591 VRLEV 595
Cdd:cd05725     79 ATLTV 83

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 63.12 E-value: 2.99e-12

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217265341  526 RLDCPFFGSPIPTLRWFKNGQG--SNLDGGNYHVYENGSLEIKMIRKEDQGIYTCVATNILGKAEN 589
Cdd:cd00096      2 TLTCSASGNPPPTITWYKNGKPlpPSSRDSRRSELGNGTLTISNVTLEDSGTYTCVASNSAGGSAS 67

Sixth immunoglobulin (Ig) domain of contactin; The members here are composed of the sixth immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409359 Cd Length: 102 Bit Score: 63.34 E-value: 7.41e-12

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  597 DPTRIYRMPEDQVARRGTTVQLECRVKHDPSLKLTVSW--------LKDDEPLYIGNRMKKEDDSLTIFGVAERDQGSYT 668
Cdd:cd04970      1 DATRITLAPSNADITVGENATLQCHASHDPTLDLTFTWsfngvpidLEKIEGHYRRRYGKDSNGDLEIVNAQLKHAGRYT 80

                           90
                   ....*....|....*...
gi 2217265341  669 CVASTELDQDLAKAYLTV 686
Cdd:cd04970     81 CTAQTVVDSDSASATLVV 98

Third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409390 [Multi-domain] Cd Length: 83 Bit Score: 62.41 E-value: 8.04e-12

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  603 RMPEDQVARRGTTVQLECRVKHDPSLklTVSWLKDDEPLYIGNRMKKEDDSLTIFGVAERDQGSYTCVASTELDQDLAKA 682
Cdd:cd05725      2 KRPQNQVVLVDDSAEFQCEVGGDPVP--TVRWRKEDGELPKGRYEILDDHSLKIRKVTAGDMGSYTCVAENMVGKIEASA 79


                   ....
gi 2217265341  683 YLTV 686
Cdd:cd05725     80 TLTV 83

Third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409390 [Multi-domain] Cd Length: 83 Bit Score: 61.64 E-value: 1.26e-11

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  331 SSQMVLRGMDLLLECIASGVPTPDIAWYKKGGDLPSDKAKFENfNKALRITNVSEEDSGEYFCLASNKMGSIRHTISVRV 410
Cdd:cd05725      5 QNQVVLVDDSAEFQCEVGGDPVPTVRWRKEDGELPKGRYEILD-DHSLKIRKVTAGDMGSYTCVAENMVGKIEASATLTV 83

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409570 [Multi-domain] Cd Length: 88 Bit Score: 62.02 E-value: 1.44e-11

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  507 PRMLSPRNQLIRVILYNRTRLDCPFFGSPIPTLRWFKNGQGSNLDGGNYHVyENGSLEIKMIRKEDQGIYTCVATNILGK 586
Cdd:cd20978      1 PKFIQKPEKNVVVKGGQDVTLPCQVTGVPQPKITWLHNGKPLQGPMERATV-EDGTLTIINVQPEDTGYYGCVATNEIGD 79


                   ....*....
gi 2217265341  587 AENQVRLEV 595
Cdd:cd20978     80 IYTETLLHV 88

Second immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structures of this group show that the second Ig domain lacks this strand and thus belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules, including vascular (VCAM), intercellular (ICAM), neural (NCAM) and mucosal addressin (MADCAM) cell adhesion molecules, as well as junction adhesion molecules (JAM).

Pssm-ID: 409557 Cd Length: 101 Bit Score: 62.27 E-value: 1.47e-11

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  231 EGAPLTLQCNPPPGLPSPVIFW--MSSSMEPI---TQDKRVSQGHNGDLYFSNVMLQDMQTDYS--CNAR 293
Cdd:cd20965     16 EGKPFKLDCNVPPGYPKPTIEWkkQLVSDSSKadtILDRRITISPNGDLYFTNVTKEDVSTDYKyvCVAK 85

Fifth immunoglobulin (Ig) domain of contactin; The members here are composed of the fifth immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409358 [Multi-domain] Cd Length: 89 Bit Score: 61.71 E-value: 1.51e-11

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  514 NQLIRVILYNRTR---LDCPFFGSPIPTLRWFKNGQgsNL-DGGNYHVYENGSLEIKMIRKEDQGIYTCVATNILGKAEN 589
Cdd:cd04969      6 NPVKKKILAAKGGdviIECKPKASPKPTISWSKGTE--LLtNSSRICILPDGSLKIKNVTKSDEGKYTCFAVNFFGKANS 83


                   ....*.
gi 2217265341  590 QVRLEV 595
Cdd:cd04969     84 TGSLSV 89

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409389 [Multi-domain] Cd Length: 87 Bit Score: 61.65 E-value: 1.86e-11

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2217265341  527 LDC-PFFGSPIPTLRWFKNGQGSNLDGGNYHVYENGSLEIKMIRKEDQGIYTCVATNILGKAENQV-RLEV 595
Cdd:cd05724     17 LECsPPRGHPEPTVSWRKDGQPLNLDNERVRIVDDGNLLIAEARKSDEGTYKCVATNMVGERESRAaRLSV 87

Fibronectin type 3 domain; One of three types of internal repeats found in the plasma protein fibronectin. Its tenth fibronectin type III repeat contains an RGD cell recognition sequence in a flexible loop between 2 strands. Approximately 2% of all animal proteins contain the FN3 repeat; including extracellular and intracellular proteins, membrane spanning cytokine receptors, growth hormone receptors, tyrosine phosphatase receptors, and adhesion molecules. FN3-like domains are also found in bacterial glycosyl hydrolases.

Pssm-ID: 238020 [Multi-domain] Cd Length: 93 Bit Score: 61.36 E-value: 2.26e-11

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341 1009 PSAPRRFRVRQPNLETINLEWDHPEHPNGIMIGYTLKYVAFNGTKVgkQIVENFSPNQTKFTVQRTDPVSRYRFTLSART 1088
Cdd:cd00063      1 PSPPTNLRVTDVTSTSVTLSWTPPEDDGGPITGYVVEYREKGSGDW--KEVEVTPGSETSYTLTGLKPGTEYEFRVRAVN 78

                           90
                   ....*....|..
gi 2217265341 1089 QVGSGEAVTEES 1100
Cdd:cd00063     79 GGGESPPSESVT 90

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 60.66 E-value: 2.61e-11

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  117 PPTITKQSaKDHIVDPRDNILIECEAKGNPAPSFHWTRNSRFFNIAKDPRVSMRRRSGTLVIDFRSggrpEEYEGEYQCF 196
Cdd:pfam13927    1 KPVITVSP-SSVTVREGETVTLTCEATGSPPPTITWYKNGEPISSGSTRSRSLSGSNSTLTISNVT----RSDAGTYTCV 75


                   ...
gi 2217265341  197 ARN 199
Cdd:pfam13927   76 ASN 78

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 60.98 E-value: 2.80e-11

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341   605 PEDQVARRGTTVQLECRVKHDPSLklTVSWLKDD-EPLYIGNRMK----KEDDSLTIFGVAERDQGSYTCVASTELDQDL 679
Cdd:smart00410    1 PPSVTVKEGESVTLSCEASGSPPP--EVTWYKQGgKLLAESGRFSvsrsGSTSTLTISNVTPEDSGTYTCAATNSSGSAS 78


                    ....*..
gi 2217265341   680 AKAYLTV 686
Cdd:smart00410   79 SGTTLTV 85

Fibronectin type 3 domain; One of three types of internal repeat within the plasma protein, fibronectin. The tenth fibronectin type III repeat contains a RGD cell recognition sequence in a flexible loop between 2 strands. Type III modules are present in both extracellular and intracellular proteins.

Pssm-ID: 214495 [Multi-domain] Cd Length: 83 Bit Score: 60.32 E-value: 4.86e-11

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341   705 PDRPRDLELTDLAERSVRLTWIP--GDANNSPITDYVVQFEEDQFQpgvWHDHSKyPGSVNSAVLR-LSPYVNYQFRVIA 781
Cdd:smart00060    1 PSPPSNLRVTDVTSTSVTLSWEPppDDGITGYIVGYRVEYREEGSE---WKEVNV-TPSSTSYTLTgLKPGTEYEFRVRA 76


                    ....*..
gi 2217265341   782 INEVGSS 788
Cdd:smart00060   77 VNGAGEG 83

Fibronectin type 3 domain; One of three types of internal repeat within the plasma protein, fibronectin. The tenth fibronectin type III repeat contains a RGD cell recognition sequence in a flexible loop between 2 strands. Type III modules are present in both extracellular and intracellular proteins.

Pssm-ID: 214495 [Multi-domain] Cd Length: 83 Bit Score: 59.94 E-value: 6.21e-11

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  1009 PSAPRRFRVRQPNLETINLEWDHPEHPNGImiGYTLKYVAFNGTKVGKQIVENFSPNQTKFTVQRTDPVSRYRFTLSART 1088
Cdd:smart00060    1 PSPPSNLRVTDVTSTSVTLSWEPPPDDGIT--GYIVGYRVEYREEGSEWKEVNVTPSSTSYTLTGLKPGTEYEFRVRAVN 78


                    ....*
gi 2217265341  1089 QVGSG 1093
Cdd:smart00060   79 GAGEG 83

Fourth Ig domain of the neural cell adhesion molecule contactin-2, and similar domains; The members here are composed of the fourth Ig domain of the neural cell adhesion molecule contactin-2. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (also called TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. The first four Ig domains form the intermolecular binding fragment which arranges as a compact U-shaped module by contacts between Ig domains 1 and 4, and domains 2 and 3. It has been proposed that a linear zipper-like array forms, from contactin-2 molecules alternatively provided by the two apposed membranes.

Pssm-ID: 143205 [Multi-domain] Cd Length: 85 Bit Score: 59.92 E-value: 7.16e-11

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217265341  338 GMDLLLECIASGVPTPDIAWYKKGGDLPSDKaKFENFNKALRITNVSEEDSGEYFCLASNKMGSIRHTISVRV 410
Cdd:cd05728     14 GSSLRWECKASGNPRPAYRWLKNGQPLASEN-RIEVEAGDLRITKLSLSDSGMYQCVAENKHGTIYASAELAV 85

Fourth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409548 [Multi-domain] Cd Length: 96 Bit Score: 59.50 E-value: 1.03e-10

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  320 TPSFMYpqgTASSQMVLRGMDLLLECIASGVPTPDIAWYKKGGDLP-SDKAKFENF-------NKALRITNVSEEDSGEY 391
Cdd:cd20956      1 APVLLE---TFSEQTLQPGPSVSLKCVASGNPLPQITWTLDGFPIPeSPRFRVGDYvtsdgdvVSYVNISSVRVEDGGEY 77

                           90
                   ....*....|....*....
gi 2217265341  392 FCLASNKMGSIRHTISVRV 410
Cdd:cd20956     78 TCTATNDVGSVSHSARINV 96

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 58.73 E-value: 1.39e-10

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217265341  506 PPRMLSPRNQLIrVILYNRTRLDCPFFGSPIPTLRWFKNGQ--GSNLDGGNYHVYENGSLEIKMIRKEDQGIYTCVATN 582
Cdd:pfam13927    1 KPVITVSPSSVT-VREGETVTLTCEATGSPPPTITWYKNGEpiSSGSTRSRSLSGSNSTLTISNVTRSDAGTYTCVASN 78

Fourth Ig-like domain from smooth muscle myosin light chain kinase and similar domains ; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain from smooth muscle myosin light chain kinase (MYLK) and similar domains. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of this group shows that the fourth Ig-like domain from myosin light chain kinase lacks this strand and thus belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409568 [Multi-domain] Cd Length: 90 Bit Score: 58.80 E-value: 1.65e-10

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217265341  335 VLRGMDLLLECIASGVPTPDIAWYKKGGDLPSDKAKF--ENFNKALRITNVSEEDSGEYFCLASNKMGSIRHTISVRV 410
Cdd:cd20976     13 AVEGQDFVAQCSARGKPVPRITWIRNAQPLQYAADRStcEAGVGELHIQDVLPEDHGTYTCLAKNAAGQVSCSAWVTV 90

Sixth immunoglobulin (Ig) domain of contactin-2; The members here are composed of the sixth immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-2-like. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. It may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module by contacts between IG domains 1 and 4, and domains 2 and 3. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-2 is also expressed in retinal amacrine cells (AC) in the developing chick retina, corresponding to the period of formation and maturation of AC processes.

Pssm-ID: 409440 Cd Length: 102 Bit Score: 59.29 E-value: 1.68e-10

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  597 DPTRIYRMPEDQVARRGTTVQLECRVKHDPSLKLTVSWLKDDEPL--------YIGNRMKKEDDSLTIFGVAERDQGSYT 668
Cdd:cd05854      1 DATKITLAPSSADINQGENLTLQCHASHDPTMDLTFTWSLDDFPIdldkpnghYRRMEVKETIGDLVIVNAQLSHAGTYT 80

                           90
                   ....*....|....*...
gi 2217265341  669 CVASTELDQDLAKAYLTV 686
Cdd:cd05854     81 CTAQTVVDSASASATLVV 98

Seventh immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the seventh immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409546 [Multi-domain] Cd Length: 96 Bit Score: 58.09 E-value: 3.91e-10

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217265341  335 VLRGMDLLLECIASGVPTPDIAWYKKGGDLPSDKAKF--ENF-----NKALRITNVSEEDSGEYFCLASNKMGS 401
Cdd:cd20954     13 VAAGQDVMLHCQADGFPTPTVTWKKATGSTPGEYKDLlyDPNvrilpNGTLVFGHVQKENEGHYLCEAKNGIGS 86

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor, and similar domains; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three Ig-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans. This group also contains fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409393 [Multi-domain] Cd Length: 95 Bit Score: 58.00 E-value: 4.29e-10

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217265341  343 LECIASGVPTPDIAWYKKGGDLPSDKA----KFENFNKALRITNVSEEDSGEYFCLASNKMGSIRHTISVRV 410
Cdd:cd05729     24 LECGAGGNPMPNITWLKDGKEFKKEHRiggtKVEEKGWSLIIERAIPRDKGKYTCIVENEYGSINHTYDVDV 95

First immunoglobulin (Ig) domain of contactin-5; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-5. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains, anchored to the membrane by glycosylphosphatidylinositol. The different contactins show different expression patterns in the central nervous system. In rats, a lack of contactin-5 (NB-2) results in an impairment of the neuronal activity in the auditory system. Contactin-5 is expressed specifically in the postnatal nervous system, peaking at about 3 weeks postnatal. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala; lower levels of expression have been detected in the corpus callosum, caudate nucleus, and spinal cord. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409435 Cd Length: 96 Bit Score: 57.65 E-value: 4.85e-10

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  127 DHIVDPRDN----ILIECEAKGNPAPSFHWTRNSRFFNIAKDPRVSMrrRSGTLVIDfrsggRPEEYE--GEYQCFARNK 200
Cdd:cd05848      9 DDAIFPTDSdekkVILNCEARGNPVPTYRWLRNGTEIDTESDYRYSL--IDGNLIIS-----NPSEVKdsGRYQCLATNS 81

                           90
                   ....*....|..
gi 2217265341  201 FGTALSNRIRLQ 212
Cdd:cd05848     82 IGSILSREALLQ 93

First immunoglobulin (Ig)-like constant domain in Robo (roundabout) receptors, and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain in Roundabout (Robo) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit1, Slit2, Slit3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit1, Slit2,and Slit3 are expressed at the ventral midline. Robo3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site.

Pssm-ID: 409490 [Multi-domain] Cd Length: 99 Bit Score: 57.95 E-value: 5.05e-10

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  118 PTITKQSaKDHIVDPRDNILIECEAKGNPAPSFHWTRNSRFFNIAKDPRVSMRR--RSGTLV-IDFRSGGRPEEYEGEYQ 194
Cdd:cd07693      1 PRIVEHP-SDLIVSKGDPATLNCKAEGRPTPTIQWLKNGQPLETDKDDPRSHRIvlPSGSLFfLRVVHGRKGRSDEGVYV 79

                           90       100
                   ....*....|....*....|
gi 2217265341  195 CFARNKFGTALSNRIRLQVS 214
Cdd:cd07693     80 CVAHNSLGEAVSRNASLEVA 99

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

Pssm-ID: 409544 [Multi-domain] Cd Length: 87 Bit Score: 57.12 E-value: 7.37e-10

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  605 PEDQVARRGTTVQLECRVKHDPSLklTVSWLKDDEPLYIGN-RMKK-EDDSLTIFGVAERDQGSYTCVASTELDQDLAKA 682
Cdd:cd20952      6 PQNQTVAVGGTVVLNCQATGEPVP--TISWLKDGVPLLGKDeRITTlENGSLQIKGAEKSDTGEYTCVALNLSGEATWSA 83


                   ....
gi 2217265341  683 YLTV 686
Cdd:cd20952     84 VLDV 87

Second Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409564 [Multi-domain] Cd Length: 91 Bit Score: 56.44 E-value: 1.15e-09

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217265341  332 SQMVLRGMDLLLECIASGVPTPDIAWYKKGGDL---PSDKAKFENFNKALRITNVSEEDSGEYFCLASNKMGS 401
Cdd:cd20972     10 SQEVAEGSKVRLECRVTGNPTPVVRWFCEGKELqnsPDIQIHQEGDLHSLIIAEAFEEDTGRYSCLATNSVGS 82

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor_like-1(FGFRL1); member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 is comprised of a signal peptide, three extracellular Ig-like modules, a transmembrane segment, and a short intracellular domain. FGFRL1 is expressed preferentially in skeletal tissues. Similar to FGF receptors, the expressed protein interacts specifically with heparin and with FGF2. FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409442 Cd Length: 92 Bit Score: 56.41 E-value: 1.18e-09

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  326 PQGTASSQMVLR------GMDLLLECIASGVPTPDIAWYKKGGDLPSDKAKFENFNK-ALRITNVSEEDSGEYFCLASNK 398
Cdd:cd05856      1 PRFTQPAKMRRRviarpvGSSVRLKCVASGNPRPDITWLKDNKPLTPPEIGENKKKKwTLSLKNLKPEDSGKYTCHVSNR 80

                           90
                   ....*....|..
gi 2217265341  399 MGSIRHTISVRV 410
Cdd:cd05856     81 AGEINATYKVDV 92

Immunoglobulin domain I1 of the titin I-band and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin domain I1 of the titin I-band and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig I1 domain of the titin I-band is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409543 [Multi-domain] Cd Length: 94 Bit Score: 56.66 E-value: 1.20e-09

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217265341  428 GEDGRLVCRANGNPKPTVQWMVNGEPLQSAPPNPNREVAGD----TIIFRDTQISSRAVYQCNTSNEHGYLLANAFVSV 502
Cdd:cd20951     15 KSDAKLRVEVQGKPDPEVKWYKNGVPIDPSSIPGKYKIESEygvhVLHIRRVTVEDSAVYSAVAKNIHGEASSSASVVV 93

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 56.03 E-value: 1.30e-09

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217265341  605 PEDQVARRGTTVQLECRVKHDPslKLTVSWLKDDEPLYIGNRMKKEDD----SLTIFGVAERDQGSYTCVAS 672
Cdd:pfam13927    8 PSSVTVREGETVTLTCEATGSP--PPTITWYKNGEPISSGSTRSRSLSgsnsTLTISNVTRSDAGTYTCVAS 77

Fifth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409550 [Multi-domain] Cd Length: 89 Bit Score: 56.04 E-value: 1.67e-09

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2217265341  524 RTRLDCPFFGSPIPTLRWFKNGQgsNL-DGGNYHVYENGSLEIKMI-RKEDQGIYTCVATN 582
Cdd:cd20958     17 TLRLHCPVAGYPISSITWEKDGR--RLpLNHRQRVFPNGTLVIENVqRSSDEGEYTCTARN 75

Third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule 1 (NCAM-1); member of the I-set of IgSF domains; The members here are composed of the third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule (NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-non-NCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions) through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain.

Pssm-ID: 143207 [Multi-domain] Cd Length: 95 Bit Score: 56.09 E-value: 1.67e-09

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217265341  338 GMDLLLECIASGVPTPDIAWYKKGGDLPSDKAKFeNFNK---ALRITNVSEEDSGEYFCLASNKMGSIRHTISVRVKA 412
Cdd:cd05730     18 GQSVTLACDADGFPEPTMTWTKDGEPIESGEEKY-SFNEdgsEMTILDVDKLDEAEYTCIAENKAGEQEAEIHLKVFA 94

Fifth immunoglobulin (Ig) domain of contactin; The members here are composed of the fifth immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409358 [Multi-domain] Cd Length: 89 Bit Score: 55.93 E-value: 1.71e-09

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217265341  335 VLRGMDLLLECIASGVPTPDIAWYKKGGDLPSDKAKFENFNKALRITNVSEEDSGEYFCLASNKMGSIRHTISVRV 410
Cdd:cd04969     14 AAKGGDVIIECKPKASPKPTISWSKGTELLTNSSRICILPDGSLKIKNVTKSDEGKYTCFAVNFFGKANSTGSLSV 89

agrin-responsive first immunoglobulin-like domains (Ig1) of the MuSK ectodomain; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domains (Ig1) of the Muscle-specific kinase (MuSK). MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409562 [Multi-domain] Cd Length: 92 Bit Score: 55.98 E-value: 1.72e-09

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217265341  335 VLRGMDLLLECIASGVPTPDIAWYKKGG--DLPSDKAKFENFNKALRITNVSEEDSGEYFCLASNKM-GSIRHTISVRV 410
Cdd:cd20970     14 AREGENATFMCRAEGSPEPEISWTRNGNliIEFNTRYIVRENGTTLTIRNIRRSDMGIYLCIASNGVpGSVEKRITLQV 92

Immunoglobulin domain; This family contains immunoglobulin-like domains.

Pssm-ID: 464046 [Multi-domain] Cd Length: 78 Bit Score: 55.65 E-value: 1.74e-09

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217265341  419 EPKNLILAPGEDGRLVCRANGNPKPTVQWMVNGEPLQSAPPNPNREVAGD-TIIFRDTQISSRAVYQCNTSN 489
Cdd:pfam13927    7 SPSSVTVREGETVTLTCEATGSPPPTITWYKNGEPISSGSTRSRSLSGSNsTLTISNVTRSDAGTYTCVASN 78

Third immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the third immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143222 [Multi-domain] Cd Length: 74 Bit Score: 55.33 E-value: 1.89e-09

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....*....
gi 2217265341  345 CIASGVPTPDIAWYKKGGDLPSDKAKFENFNKALRITNVSEEDSGEYFCLASNKMGSIR 403
Cdd:cd05745      9 CEAQGYPQPVIAWTKGGSQLSVDRRHLVLSSGTLRISRVALHDQGQYECQAVNIVGSQR 67

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

Pssm-ID: 409544 [Multi-domain] Cd Length: 87 Bit Score: 55.58 E-value: 2.26e-09

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  333 QMVLRGMDLLLECIASGVPTPDIAWYKKGGDLPSDKAKFENF-NKALRITNVSEEDSGEYFCLASNKMGS 401
Cdd:cd20952      9 QTVAVGGTVVLNCQATGEPVPTISWLKDGVPLLGKDERITTLeNGSLQIKGAEKSDTGEYTCVALNLSGE 78

Fibronectin type 3 domain [General function prediction only];

Pssm-ID: 442628 [Multi-domain] Cd Length: 603 Bit Score: 61.94 E-value: 2.34e-09

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  679 LAKAYLTVLADQATPTNRLAALPKGRPDRPRDLELTDLAERSVRLTWIPGDANNSPITDYVVQFEEDQFQPGVwhDHSKY 758
Cdd:COG3401    111 LTSSDEVPSPAVGTATTATAVAGGAATAGTYALGAGLYGVDGANASGTTASSVAGAGVVVSPDTSATAAVATT--SLTVT 188

                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  759 PGSVNSAVLRLSPYVNYQFRVIAINEVGSSHPSlPSERYRTSGAPPESnPGDVKGEGTRKNNMEITWTPMNATSAFGpnl 838
Cdd:COG3401    189 STTLVDGGGDIEPGTTYYYRVAATDTGGESAPS-NEVSVTTPTTPPSA-PTGLTATADTPGSVTLSWDPVTESDATG--- 263

                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  839 rYIVKwRRRETREAWNNV-TVWGSRYVV-----GQTpvyvpYEIRVQAENDFGKGPEPESVIGYSGEDYPRAAPTEVKVR 912
Cdd:COG3401    264 -YRVY-RSNSGDGPFTKVaTVTTTSYTDtgltnGTT-----YYYRVTAVDAAGNESAPSNVVSVTTDLTPPAAPSGLTAT 336

                          250       260       270
                   ....*....|....*....|....*....|....*
gi 2217265341  913 VMNSTAISLQWNRVYSDTVQGqlreYRAYYWRESS 947
Cdd:COG3401    337 AVGSSSITLSWTASSDADVTG----YNVYRSTSGG 367

Immunoglobulin (Ig)-like ectodomain of the LRIG1 (Leucine-rich Repeats And Immunoglobulin-like Domains Protein 1) and similar proteins; member of the I-set of IgSF domains; The members here are composed of subgroup of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. The ectodomain of LRIG1 has two distinct regions: the proposed 15 LRRs and three Ig-like domains closer to the membrane. LRIG1 has been reported to interact with many receptor tyrosine kinases, GDNF/c-Ret, E-cadherin, JAK/STAT, c-Met, and the EGFR family signaling systems. Immunoglobulin Superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The structure of the LRIG1 extracellular Ig domain lacks a C" strand and thus is better described as a member of the I-set of IgSF domains.

Pssm-ID: 409420 [Multi-domain] Cd Length: 91 Bit Score: 55.70 E-value: 2.58e-09

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217265341  343 LECIASGVPTPDIAWYKKGG-DLPSDKAKFENF---NKALRITNVSEEDSGEYFCLASNKMGSI 402
Cdd:cd05763     19 LECAATGHPTPQIAWQKDGGtDFPAARERRMHVmpeDDVFFIVDVKIEDTGVYSCTAQNSAGSI 82

Fibronectin type III domain;

Pssm-ID: 394996 [Multi-domain] Cd Length: 85 Bit Score: 55.11 E-value: 3.01e-09

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341 1010 SAPRRFRVRQPNLETINLEWDHPEHPNGIMIGYTLKYVAFNGTKVGKQIVEnfSPNQTKFTVQRTDPVSRYRFTLSARTQ 1089
Cdd:pfam00041    1 SAPSNLTVTDVTSTSLTVSWTPPPDGNGPITGYEVEYRPKNSGEPWNEITV--PGTTTSVTLTGLKPGTEYEVRVQAVNG 78


                   ....*
gi 2217265341 1090 VGSGE 1094
Cdd:pfam00041   79 GGEGP 83

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 54.26 E-value: 3.71e-09

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217265341  432 RLVCRANGNPKPTVQWMVNGEPLQSAPPNPNREVAGD-TIIFRDTQISSRAVYQCNTSNEHG 492
Cdd:cd00096      2 TLTCSASGNPPPTITWYKNGKPLPPSSRDSRRSELGNgTLTISNVTLEDSGTYTCVASNSAG 63

First immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409387 Cd Length: 97 Bit Score: 55.18 E-value: 4.09e-09

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  133 RDNILIECEAKGNPAPSFHWTRNSRFFNIAKDPRVSMrRRSGTLVID---FRSGGRPEeyEGEYQCFARNK-FGTALSNR 208
Cdd:cd05722     16 GGPVVLNCSAESDPPPKIEWKKDGVLLNLVSDERRQQ-LPNGSLLITsvvHSKHNKPD--EGFYQCVAQNEsLGSIVSRT 92


                   ....*
gi 2217265341  209 IRLQV 213
Cdd:cd05722     93 ARVTV 97

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409570 [Multi-domain] Cd Length: 88 Bit Score: 54.71 E-value: 5.10e-09

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217265341  335 VLRGMDLLLECIASGVPTPDIAWYKKGGDL--PSDKAKFENFnkALRITNVSEEDSGEYFCLASNKMGSIRHTISVRV 410
Cdd:cd20978     13 VKGGQDVTLPCQVTGVPQPKITWLHNGKPLqgPMERATVEDG--TLTIINVQPEDTGYYGCVATNEIGDIYTETLLHV 88

agrin-responsive first immunoglobulin-like domains (Ig1) of the MuSK ectodomain; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domains (Ig1) of the Muscle-specific kinase (MuSK). MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409562 [Multi-domain] Cd Length: 92 Bit Score: 54.82 E-value: 5.24e-09

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2217265341  527 LDCPFFGSPIPTLRWFKNGQGSNLDGGNYHVYENGS-LEIKMIRKEDQGIYTCVATN-ILGKAENQVRLEV 595
Cdd:cd20970     22 FMCRAEGSPEPEISWTRNGNLIIEFNTRYIVRENGTtLTIRNIRRSDMGIYLCIASNgVPGSVEKRITLQV 92

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 54.19 E-value: 6.58e-09

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  414 PYWLDEPKNLILAPGEDGRLVCRANGNPKPTVQWMVNGEPLQSAPPNPNREVAGD-TIIFRDTQISSRAVYQCNTSNEHG 492
Cdd:pfam07679    1 PKFTQKPKDVEVQEGESARFTCTVTGTPDPEVSWFKDGQPLRSSDRFKVTYEGGTyTLTISNVQPDDSGKYTCVATNSAG 80

                           90
                   ....*....|
gi 2217265341  493 YLLANAFVSV 502
Cdd:pfam07679   81 EAEASAELTV 90

Third immunoglobulin (Ig) domain of contactin-1; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 143259 Cd Length: 88 Bit Score: 53.87 E-value: 8.24e-09

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217265341  336 LRGMDLLLECIASGVPTPDIAWYKKGGDLPSdKAKFENFNKALRITNVSEEDSGEYFCLASNKMGSIRHTISVRVK 411
Cdd:cd05851     14 LKGQNVTLECFALGNPVPVIRWRKILEPMPA-TAEISMSGAVLKIFNIQPEDEGTYECEAENIKGKDKHQARVYVQ 88

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 53.10 E-value: 1.14e-08

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217265341  616 VQLECRVKHDPslKLTVSWLKDDEPL----YIGNRMKKEDDSLTIFGVAERDQGSYTCVASTEL 675
Cdd:cd00096      1 VTLTCSASGNP--PPTITWYKNGKPLppssRDSRRSELGNGTLTISNVTLEDSGTYTCVASNSA 62

First immunoglobulin (Ig)-like constant domain in Robo (roundabout) receptors, and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain in Roundabout (Robo) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit1, Slit2, Slit3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit1, Slit2,and Slit3 are expressed at the ventral midline. Robo3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site.

Pssm-ID: 409490 [Multi-domain] Cd Length: 99 Bit Score: 53.71 E-value: 1.28e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  414 PYWLDEPKNLILAPGEDGRLVCRANGNPKPTVQWMVNGEPLQS--APPNPNREVAGDTIIFRDTQISSR------AVYQC 485
Cdd:cd07693      1 PRIVEHPSDLIVSKGDPATLNCKAEGRPTPTIQWLKNGQPLETdkDDPRSHRIVLPSGSLFFLRVVHGRkgrsdeGVYVC 80


                   ....*..
gi 2217265341  486 NTSNEHG 492
Cdd:cd07693     81 VAHNSLG 87

Third immunoglobulin (Ig) domain of contactin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409357 [Multi-domain] Cd Length: 88 Bit Score: 53.32 E-value: 1.39e-08

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2217265341  336 LRGMDLLLECIASGVPTPDIAWYKKGGDLPSDKAKFENfNKALRITNVSEEDSGEYFCLASNKMG 400
Cdd:cd04968     14 LKGQTVTLECFALGNPVPQIKWRKVDGSPSSQWEITTS-EPVLEIPNVQFEDEGTYECEAENSRG 77

Immunoglobulin domain I1 of the titin I-band and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin domain I1 of the titin I-band and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig I1 domain of the titin I-band is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409543 [Multi-domain] Cd Length: 94 Bit Score: 53.58 E-value: 1.40e-08

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217265341  526 RLDCPFFGSPIPTLRWFKNGQ--GSNLDGGNYHVYENG---SLEIKMIRKEDQGIYTCVATNILGKAENQVRLEVK 596
Cdd:cd20951     19 KLRVEVQGKPDPEVKWYKNGVpiDPSSIPGKYKIESEYgvhVLHIRRVTVEDSAVYSAVAKNIHGEASSSASVVVE 94

Immunoglobulin (Ig)-like domain in neuregulins; The members here are composed of the immunoglobulin (Ig)-like domain in neuregulins (NRGs). NRGs are signaling molecules which participate in cell-cell interactions in the nervous system, breast, heart, and other organ systems, and are implicated in the pathology of diseases including schizophrenia, multiple sclerosis, and breast cancer. There are four members of the neuregulin gene family (NRG-1, NRG-2, NRG-3, and NRG-4). The NRG-1 protein, binds to and activates the tyrosine kinases receptors ErbB3 and ErbB4, initiating signaling cascades. The other NRGs proteins bind one or the other or both of these ErbBs. NRG-1 has multiple functions: in the brain it regulates various processes such as radial glia formation and neuronal migration, dendritic development, and expression of neurotransmitters receptors, while in the peripheral nervous system NRG-1 regulates processes such as target cell differentiation, and Schwann cell survival. There are many NRG-1 isoforms which arise from the alternative splicing of mRNA. Less is known of the functions of the other NRGs. NRG-2 and NRG-3 are expressed predominantly in the nervous system. NRG-2 is expressed by motor neurons and terminal Schwann cells, and is concentrated near synaptic sites and may be a signal that regulates synaptic differentiation. NRG-4 has been shown to direct pancreatic islet cell development towards the delta-cell lineage.

Pssm-ID: 409408 [Multi-domain] Cd Length: 92 Bit Score: 53.28 E-value: 1.46e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  332 SQMVLRGMDLLLECIASGV-PTPDIAWYKKGGDL---PSDKAKFENFNKA--LRITNVSEEDSGEYFCLASNKMGSIRHT 405
Cdd:cd05750      8 SQTVQEGSKLVLKCEATSEnPSPRYRWFKDGKELnrkRPKNIKIRNKKKNseLQINKAKLEDSGEYTCVVENILGKDTVT 87


                   ....*
gi 2217265341  406 ISVRV 410
Cdd:cd05750     88 GNVTV 92

Fibronectin type 3 domain; One of three types of internal repeats found in the plasma protein fibronectin. Its tenth fibronectin type III repeat contains an RGD cell recognition sequence in a flexible loop between 2 strands. Approximately 2% of all animal proteins contain the FN3 repeat; including extracellular and intracellular proteins, membrane spanning cytokine receptors, growth hormone receptors, tyrosine phosphatase receptors, and adhesion molecules. FN3-like domains are also found in bacterial glycosyl hydrolases.

Pssm-ID: 238020 [Multi-domain] Cd Length: 93 Bit Score: 53.65 E-value: 1.47e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  905 APTEVKVRVMNSTAISLQWNRVYSDtvQGQLREYRAYYWRESSllknlwvSQKRQQASFPGDRLRGVVSRLFPYSNYKLE 984
Cdd:cd00063      3 PPTNLRVTDVTSTSVTLSWTPPEDD--GGPITGYVVEYREKGS-------GDWKEVEVTPGSETSYTLTGLKPGTEYEFR 73

                           90       100
                   ....*....|....*....|
gi 2217265341  985 MVVVNGRGDGPRSETKEFTT 1004
Cdd:cd00063     74 VRAVNGGGESPPSESVTVTT 93

Fourth Ig domain of the neural cell adhesion molecule contactin-2, and similar domains; The members here are composed of the fourth Ig domain of the neural cell adhesion molecule contactin-2. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (also called TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. The first four Ig domains form the intermolecular binding fragment which arranges as a compact U-shaped module by contacts between Ig domains 1 and 4, and domains 2 and 3. It has been proposed that a linear zipper-like array forms, from contactin-2 molecules alternatively provided by the two apposed membranes.

Pssm-ID: 143205 [Multi-domain] Cd Length: 85 Bit Score: 52.99 E-value: 1.61e-08

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217265341  521 LYNRTRLDCPFFGSPIPTLRWFKNGQGSNLDGGNYhvYENGSLEIKMIRKEDQGIYTCVATN 582
Cdd:cd05728     13 IGSSLRWECKASGNPRPAYRWLKNGQPLASENRIE--VEAGDLRITKLSLSDSGMYQCVAEN 72

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

Pssm-ID: 464026 [Multi-domain] Cd Length: 79 Bit Score: 52.78 E-value: 1.65e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  326 PQGTASSQMVLRGMDLLLECIASGVPTPDIAWYKKGGDLPSDKAKFenfnkalrITNVSEEDSGEYFCLASNKMGSIR-- 403
Cdd:pfam13895    2 PVLTPSPTVVTEGEPVTLTCSAPGNPPPSYTWYKDGSAISSSPNFF--------TLSVSAEDSGTYTCVARNGRGGKVsn 73


                   ....*.
gi 2217265341  404 -HTISV 408
Cdd:pfam13895   74 pVELTV 79

First immunoglobulin (Ig) domain of contactin; member of the I-set of (Ig) superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409356 [Multi-domain] Cd Length: 96 Bit Score: 53.40 E-value: 1.69e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  127 DHIVDPRDN----ILIECEAKGNPAPSFHWTRNSRFFNIAKDPRVSMrrRSGTLVIDfrsggRPEEYE--GEYQCFARNK 200
Cdd:cd04967      9 DDTIFPEDSdekkVALNCRARANPVPSYRWLMNGTEIDLESDYRYSL--VDGTLVIS-----NPSKAKdaGHYQCLATNT 81

                           90
                   ....*....|..
gi 2217265341  201 FGTALSNRIRLQ 212
Cdd:cd04967     82 VGSVLSREATLQ 93

Fibronectin type 3 domain; One of three types of internal repeats found in the plasma protein fibronectin. Its tenth fibronectin type III repeat contains an RGD cell recognition sequence in a flexible loop between 2 strands. Approximately 2% of all animal proteins contain the FN3 repeat; including extracellular and intracellular proteins, membrane spanning cytokine receptors, growth hormone receptors, tyrosine phosphatase receptors, and adhesion molecules. FN3-like domains are also found in bacterial glycosyl hydrolases.

Pssm-ID: 238020 [Multi-domain] Cd Length: 93 Bit Score: 53.27 E-value: 1.84e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  806 SNPGDVKGEGTRKNNMEITWTPmnATSAFGPNLRYIVKWRRRETREaWNNVTVWGS---RYVVGQTPVYVPYEIRVQAEN 882
Cdd:cd00063      2 SPPTNLRVTDVTSTSVTLSWTP--PEDDGGPITGYVVEYREKGSGD-WKEVEVTPGsetSYTLTGLKPGTEYEFRVRAVN 78

                           90
                   ....*....|....
gi 2217265341  883 DFGKGPEPESVIGY 896
Cdd:cd00063     79 GGGESPPSESVTVT 92

immunoglobulin-like domain of telokin and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin (Ig) domain in telokin, the C-terminal domain of myosin light chain kinase which is identical to telokin, and similar proteins. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the telokin Ig domain lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409565 [Multi-domain] Cd Length: 88 Bit Score: 52.58 E-value: 2.41e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  607 DQVARRGTTVQLECRVKHDPSLKltVSWLKDDEPLYIGNRMKKEDD-----SLTIFGVAERDQGSYTCVASTELDQDLAK 681
Cdd:cd20973      6 DKEVVEGSAARFDCKVEGYPDPE--VKWMKDDNPIVESRRFQIDQDedglcSLIISDVCGDDSGKYTCKAVNSLGEATCS 83


                   ....*
gi 2217265341  682 AYLTV 686
Cdd:cd20973     84 AELTV 88

Immunoglobulin (Ig)-like domain of myotilin, palladin, and myopalladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain in myotilin, palladin, and myopalladin. Myotilin, palladin, and myopalladin function as scaffolds that regulate actin organization. Myotilin and myopalladin are most abundant in skeletal and cardiac muscle; palladin is ubiquitously expressed in the organs of developing vertebrates and plays a key role in cellular morphogenesis. The three family members each interact with specific molecular partners with all three binding to alpha-actinin; In addition, palladin also binds to vasodilator-stimulated phosphoprotein (VASP) and ezrin, myotilin binds to filamin and actin, and myopalladin also binds to nebulin and cardiac ankyrin repeat protein (CARP). This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409405 [Multi-domain] Cd Length: 91 Bit Score: 52.88 E-value: 2.47e-08

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217265341  525 TRLDCPFFGSPIPTLRWFKNGQGSNLDGGN-YHVYENG--SLEIKMIRKEDQGIYTCVATNILGKAENQVRLEV 595
Cdd:cd05744     18 CRFDCKVSGLPTPDLFWQLNGKPVRPDSAHkMLVRENGrhSLIIEPVTKRDAGIYTCIARNRAGENSFNAELVV 91

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three IG-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans.

Pssm-ID: 409443 [Multi-domain] Cd Length: 95 Bit Score: 52.55 E-value: 2.84e-08

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217265341  343 LECIASGVPTPDIAWYKKGGDLPSDKA----KFENFNKALRITNVSEEDSGEYFCLASNKMGSIRHTISVRV 410
Cdd:cd05857     24 FRCPAAGNPTPTMRWLKNGKEFKQEHRiggyKVRNQHWSLIMESVVPSDKGNYTCVVENEYGSINHTYHLDV 95

Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins, including T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins, including butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E, and D strands in one sheet and A', G, F, C, C' and C" in the other. The structures in C1-set are smaller than those in the V-set; they have one beta sheet that is formed by strands A, B, E, and D and the other by strands G, F, C, and C'. Moreover, a C1-set Ig domain contains a short C' strand (three residues) and lacks A' and C" strand. Unlike other Ig domain sets, C2-set structures do not have a D strand. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409353 [Multi-domain] Cd Length: 70 Bit Score: 51.18 E-value: 4.50e-08

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217265341  138 IECEAKGNPAPSFHWTRNSRFFNIAKDPRVSMRRRSGTLVIDfrsgGRPEEYEGEYQCFARNKFGTALS 206
Cdd:cd00096      3 LTCSASGNPPPTITWYKNGKPLPPSSRDSRRSELGNGTLTIS----NVTLEDSGTYTCVASNSAGGSAS 67

Fibronectin type 3 domain [General function prediction only];

Pssm-ID: 442628 [Multi-domain] Cd Length: 603 Bit Score: 57.70 E-value: 4.59e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  849 TREAWNNVTVWGSRYVVGQTPVYVP---YEIRVQAENDFGKGPEPESVIGYSGEDYPrAAPTEVKVRVMNSTAISLQWNR 925
Cdd:COG3401    177 TAAVATTSLTVTSTTLVDGGGDIEPgttYYYRVAATDTGGESAPSNEVSVTTPTTPP-SAPTGLTATADTPGSVTLSWDP 255

                           90       100       110       120       130       140       150       160
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  926 VYSDTVQGqlreYRAYYWRES----SLLKNLwvsqkrQQASFpgdrlrgVVSRLFPYSNYKLEMVVVNGRGD-GPRSETK 1000
Cdd:COG3401    256 VTESDATG----YRVYRSNSGdgpfTKVATV------TTTSY-------TDTGLTNGTTYYYRVTAVDAAGNeSAPSNVV 318

                          170       180       190       200       210       220       230       240
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341 1001 EFTTPEGVPSAPRRFRVRQPNLETINLEWDHPehPNGIMIGYTLKYVAFNGTKVGKqIVEnfSPNQTKFTVQRTDPVSRY 1080
Cdd:COG3401    319 SVTTDLTPPAAPSGLTATAVGSSSITLSWTAS--SDADVTGYNVYRSTSGGGTYTK-IAE--TVTTTSYTDTGLTPGTTY 393

                          250       260       270       280       290
                   ....*....|....*....|....*....|....*....|....*....|....
gi 2217265341 1081 RFTLSARTQVG-----SGEAVTEESPAPPNEATPTAAPPTLPPTTVGATGAVSS 1129
Cdd:COG3401    394 YYKVTAVDAAGnesapSEEVSATTASAASGESLTASVDAVPLTDVAGATAAASA 447

Fibronectin type 3 domain; One of three types of internal repeat within the plasma protein, fibronectin. The tenth fibronectin type III repeat contains a RGD cell recognition sequence in a flexible loop between 2 strands. Type III modules are present in both extracellular and intracellular proteins.

Pssm-ID: 214495 [Multi-domain] Cd Length: 83 Bit Score: 51.46 E-value: 5.67e-08

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341   806 SNPGDVKGEGTRKNNMEITWTPMNATSAFGPNLRYIVKWrrRETREAWNNVTVWGS--RYVVGQTPVYVPYEIRVQAEND 883
Cdd:smart00060    2 SPPSNLRVTDVTSTSVTLSWEPPPDDGITGYIVGYRVEY--REEGSEWKEVNVTPSstSYTLTGLKPGTEYEFRVRAVNG 79


                    ....
gi 2217265341   884 FGKG 887
Cdd:smart00060   80 AGEG 83

First immunoglobulin (Ig) domain of contactin-2; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-2-like. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. It may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module by contacts between IG domains 1 and 4, and domains 2 and 3. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-2 is also expressed in retinal amacrine cells in the developing chick retina, corresponding to the period of formation and maturation of AC processes. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409437 [Multi-domain] Cd Length: 97 Bit Score: 51.85 E-value: 5.69e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  414 PYWLDEPKNLILAPG---EDGRLVCRANGNPKPTVQWMVNGEPLQSAPPNPNREVAGDTIIFRDTQISSRAVYQCNTSNE 490
Cdd:cd05850      3 PVFEEQPSSTLFPEGsaeEKVTLACRARASPPATYRWKMNGTELKMEPDSRYRLVAGNLVISNPVKAKDAGSYQCLASNR 82


                   ..
gi 2217265341  491 HG 492
Cdd:cd05850     83 RG 84

Fifth immunoglobulin (Ig) domain of contactin-1; The members here are composed of the fifth immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409438 Cd Length: 89 Bit Score: 51.54 E-value: 5.71e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  506 PPRMLSPRNQLIRVILYNRTRLDCPFFGSPIPTLRWFKnGQGSNLDGGNYHVYENGSLEIKMIRKEDQGIYTCVATNILG 585
Cdd:cd05852      1 PTFEFNPMKKKILAAKGGRVIIECKPKAAPKPKFSWSK-GTELLVNNSRISIWDDGSLEILNITKLDEGSYTCFAENNRG 79

                           90
                   ....*....|
gi 2217265341  586 KAENQVRLEV 595
Cdd:cd05852     80 KANSTGVLSV 89

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 51.35 E-value: 6.20e-08

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341   420 PKNLILAPGEDGRLVCRANGNPKPTVQWMVNGEPLQSAPPNPNREVAGD--TIIFRDTQISSRAVYQCNTSNEHGYLLAN 497
Cdd:smart00410    1 PPSVTVKEGESVTLSCEASGSPPPEVTWYKQGGKLLAESGRFSVSRSGStsTLTISNVTPEDSGTYTCAATNSSGSASSG 80


                    ....*
gi 2217265341   498 AFVSV 502
Cdd:smart00410   81 TTLTV 85

Third immunoglobulin (Ig) domain of contactin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409357 [Multi-domain] Cd Length: 88 Bit Score: 51.39 E-value: 6.21e-08

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217265341  527 LDCPFFGSPIPTLRWFKngqgsnLDGGNYHVYE----NGSLEIKMIRKEDQGIYTCVATNILGKAENQVRLEV 595
Cdd:cd04968     21 LECFALGNPVPQIKWRK------VDGSPSSQWEittsEPVLEIPNVQFEDEGTYECEAENSRGKDTVQGRIIV 87

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three IG-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans.

Pssm-ID: 409443 [Multi-domain] Cd Length: 95 Bit Score: 51.78 E-value: 6.51e-08

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217265341  523 NRTRLDCPFFGSPIPTLRWFKNGQGSNLDG--GNYHV-YENGSLEIKMIRKEDQGIYTCVATNILGKAENQVRLEV 595
Cdd:cd05857     20 NTVKFRCPAAGNPTPTMRWLKNGKEFKQEHriGGYKVrNQHWSLIMESVVPSDKGNYTCVVENEYGSINHTYHLDV 95

Fifth immunoglobulin (Ig) domain of contactin; The members here are composed of the fifth immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409358 [Multi-domain] Cd Length: 89 Bit Score: 51.31 E-value: 7.99e-08

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  118 PTITKQSAKDHIVDPRD-NILIECEAKGNPAPSFHWTRNSRffNIAKDPRVSMrRRSGTLVIdfRSGGRPEeyEGEYQCF 196
Cdd:cd04969      1 PDFELNPVKKKILAAKGgDVIIECKPKASPKPTISWSKGTE--LLTNSSRICI-LPDGSLKI--KNVTKSD--EGKYTCF 73

                           90
                   ....*....|
gi 2217265341  197 ARNKFGTALS 206
Cdd:cd04969     74 AVNFFGKANS 83

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 50.97 E-value: 9.16e-08

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341   126 KDHIVDPRDNILIECEAKGNPAPSFHWTRNSRFFnIAKDPRVSMRRRSGTLVIDFRSGGRpeEYEGEYQCFARNKFGTAL 205
Cdd:smart00410    2 PSVTVKEGESVTLSCEASGSPPPEVTWYKQGGKL-LAESGRFSVSRSGSTSTLTISNVTP--EDSGTYTCAATNSSGSAS 78


                    ....*...
gi 2217265341   206 SNrIRLQV 213
Cdd:smart00410   79 SG-TTLTV 85

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409549 [Multi-domain] Cd Length: 88 Bit Score: 50.99 E-value: 9.36e-08

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217265341  333 QMVLRGMDLLLECIASGVPTPDIAWYKKGGDLPSDKAKFENFNKALRITNVSEEDSGEYFCLASNKMGSIRHTISVRV 410
Cdd:cd20957     11 QTVDFGRTAVFNCSVTGNPIHTVLWMKDGKPLGHSSRVQILSEDVLVIPSVKREDKGMYQCFVRNDGDSAQATAELKL 88

Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.

Pssm-ID: 214653 [Multi-domain] Cd Length: 85 Bit Score: 50.97 E-value: 9.72e-08

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341   226 PVVVQEGAPLTLQCnPPPGLPSPVIFWMSSSMEPITQDKRVS---QGHNGDLYFSNVMLQDmQTDYSCNARfhfTHTIQQ 302
Cdd:smart00410    3 SVTVKEGESVTLSC-EASGSPPPEVTWYKQGGKLLAESGRFSvsrSGSTSTLTISNVTPED-SGTYTCAAT---NSSGSA 77


                    ....*...
gi 2217265341   303 KNPFTLKV 310
Cdd:smart00410   78 SSGTTLTV 85

Second immunoglobulin (Ig)-like domain of a Follistatin-related protein 5, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in human Follistatin-related protein 5 (FSTL5) and a follistatin-like molecule encoded by the CNS-related Mahya gene. Mahya genes have been retained in certain Bilaterian branches during evolution. They are conserved in Hymenoptera and Deuterostomes, but are absent from other metazoan species such as fruit fly and nematode. Mahya proteins are secretory, with a follistatin-like domain (Kazal-type serine/threonine protease inhibitor domain and EF-hand calcium-binding domain), two Ig-like domains, and a novel C-terminal domain. Mahya may be involved in learning and memory and in processing of sensory information in Hymenoptera and vertebrates. Follistatin is a secreted, multidomain protein that binds activins with high affinity and antagonizes their signaling.

Pssm-ID: 409399 [Multi-domain] Cd Length: 93 Bit Score: 51.11 E-value: 1.12e-07

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217265341  527 LDCPFFGSPIPTLRWFKNGQGSNLD-GGNYHVYENGS-LEIKMIRKEDQGIYTCVATNILGKAENQVRLEVKD 597
Cdd:cd05736     20 LRCHAEGIPLPRVQWLKNGMDINPKlSKQLTLIANGSeLHISNVRYEDTGAYTCIAKNEGGVDEDISSLFVED 92

Fourth Ig-like domain from smooth muscle myosin light chain kinase and similar domains ; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain from smooth muscle myosin light chain kinase (MYLK) and similar domains. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of this group shows that the fourth Ig-like domain from myosin light chain kinase lacks this strand and thus belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409568 [Multi-domain] Cd Length: 90 Bit Score: 50.71 E-value: 1.29e-07

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  527 LDCPFFGSPIPTLRWFKNGQGSNLDGGNYHV-YENGSLEIKMIRKEDQGIYTCVATNILGKAENQVRLEV 595
Cdd:cd20976     21 AQCSARGKPVPRITWIRNAQPLQYAADRSTCeAGVGELHIQDVLPEDHGTYTCLAKNAAGQVSCSAWVTV 90

First immunoglobulin (Ig) domain of contactin; member of the I-set of (Ig) superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409356 [Multi-domain] Cd Length: 96 Bit Score: 50.70 E-value: 1.42e-07

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  414 PYWLDEPKNLILAPGEDGR---LVCRANGNPKPTVQWMVNGEPLQSAPPNPNREVAGDTIIFRDTQISSRAVYQCNTSNE 490
Cdd:cd04967      2 PVFEEQPDDTIFPEDSDEKkvaLNCRARANPVPSYRWLMNGTEIDLESDYRYSLVDGTLVISNPSKAKDAGHYQCLATNT 81


                   ....*.
gi 2217265341  491 HGYLLA 496
Cdd:cd04967     82 VGSVLS 87

agrin-responsive first immunoglobulin-like domains (Ig1) of the MuSK ectodomain; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domains (Ig1) of the Muscle-specific kinase (MuSK). MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409562 [Multi-domain] Cd Length: 92 Bit Score: 50.58 E-value: 1.46e-07

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  121 TKQSAKDHIVDPRDNILIECEAKGNPAPSFHWTRNSRFFnIAKDPRVSMRRRSGTLVIdfRSGGRPEeyEGEYQCFARNK 200
Cdd:cd20970      5 TPQPSFTVTAREGENATFMCRAEGSPEPEISWTRNGNLI-IEFNTRYIVRENGTTLTI--RNIRRSD--MGIYLCIASNG 79

                           90
                   ....*....|...
gi 2217265341  201 FGTALSNRIRLQV 213
Cdd:cd20970     80 VPGSVEKRITLQV 92

Immunoglobulin domain I1 of the titin I-band and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin domain I1 of the titin I-band and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig I1 domain of the titin I-band is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409543 [Multi-domain] Cd Length: 94 Bit Score: 50.50 E-value: 1.47e-07

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  332 SQMVLRGMDLLLECIASGVPTPDIAWYKKG----GDLPSDKAKFENFN--KALRITNVSEEDSGEYFCLASNKMGSIRHT 405
Cdd:cd20951      9 SHTVWEKSDAKLRVEVQGKPDPEVKWYKNGvpidPSSIPGKYKIESEYgvHVLHIRRVTVEDSAVYSAVAKNIHGEASSS 88


                   ....*.
gi 2217265341  406 ISVRVK 411
Cdd:cd20951     89 ASVVVE 94

agrin-responsive second immunoglobulin-like domains (Ig2) of the Muscle-specific kinase (MuSK) ectodomain; a member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin-like (Ig) domains of the Muscle-specific kinase (MuSK) ectodomain. MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409560 [Multi-domain] Cd Length: 88 Bit Score: 50.32 E-value: 1.50e-07

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217265341  335 VLRGMDLLLECIASGVPTPDIAWYKkGGDLPSDKAKFENFNK-ALRITNVSEEDSGEYFCLASNKMGS 401
Cdd:cd20968     11 IIEGLKAVLPCTTMGNPKPSVSWIK-GDDLIKENNRIAVLESgSLRIHNVQKEDAGQYRCVAKNSLGI 77

agrin-responsive second immunoglobulin-like domains (Ig2) of the Muscle-specific kinase (MuSK) ectodomain; a member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin-like (Ig) domains of the Muscle-specific kinase (MuSK) ectodomain. MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409560 [Multi-domain] Cd Length: 88 Bit Score: 50.32 E-value: 1.50e-07

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  517 IRVILYNRTRLDCPFFGSPIPTLRWFKnGQGSNLDGGNYHVYENGSLEIKMIRKEDQGIYTCVATNILGKAENQ-VRLEV 595
Cdd:cd20968      9 VTIIEGLKAVLPCTTMGNPKPSVSWIK-GDDLIKENNRIAVLESGSLRIHNVQKEDAGQYRCVAKNSLGIAYSKpVTIEV 87


                   .
gi 2217265341  596 K 596
Cdd:cd20968     88 E 88

Second immunoglobulin (Ig)-like domain of a Follistatin-related protein 5, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in human Follistatin-related protein 5 (FSTL5) and a follistatin-like molecule encoded by the CNS-related Mahya gene. Mahya genes have been retained in certain Bilaterian branches during evolution. They are conserved in Hymenoptera and Deuterostomes, but are absent from other metazoan species such as fruit fly and nematode. Mahya proteins are secretory, with a follistatin-like domain (Kazal-type serine/threonine protease inhibitor domain and EF-hand calcium-binding domain), two Ig-like domains, and a novel C-terminal domain. Mahya may be involved in learning and memory and in processing of sensory information in Hymenoptera and vertebrates. Follistatin is a secreted, multidomain protein that binds activins with high affinity and antagonizes their signaling.

Pssm-ID: 409399 [Multi-domain] Cd Length: 93 Bit Score: 49.95 E-value: 2.59e-07

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217265341  343 LECIASGVPTPDIAWYKKGGDLP---SDKAKFENFNKALRITNVSEEDSGEYFCLASNKMGSIRHTISVRVK 411
Cdd:cd05736     20 LRCHAEGIPLPRVQWLKNGMDINpklSKQLTLIANGSELHISNVRYEDTGAYTCIAKNEGGVDEDISSLFVE 91

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409570 [Multi-domain] Cd Length: 88 Bit Score: 49.70 E-value: 2.79e-07

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  605 PEDQVARRGT-TVQLECRVKHDPSLKltVSWLKDDEPLyIGN--RMKKEDDSLTIFGVAERDQGSYTCVASTELDQDLAK 681
Cdd:cd20978      7 PEKNVVVKGGqDVTLPCQVTGVPQPK--ITWLHNGKPL-QGPmeRATVEDGTLTIINVQPEDTGYYGCVATNEIGDIYTE 83


                   ....*
gi 2217265341  682 AYLTV 686
Cdd:cd20978     84 TLLHV 88

Fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; Members here are composed the fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1, Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409391 [Multi-domain] Cd Length: 98 Bit Score: 49.95 E-value: 2.91e-07

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  419 EPKNLILAPGEDGRLVCRANGNPKPTVQWMVNGE-----PLQSAPPNPNREVA--GDTIIfRDTQISSRAVYQCNTSNEH 491
Cdd:cd05726      5 KPRDQVVALGRTVTFQCETKGNPQPAIFWQKEGSqnllfPYQPPQPSSRFSVSptGDLTI-TNVQRSDVGYYICQALNVA 83

                           90
                   ....*....|....
gi 2217265341  492 GYLLANAFVSVLDV 505
Cdd:cd05726     84 GSILAKAQLEVTDV 97

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor, and similar domains; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three Ig-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans. This group also contains fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409393 [Multi-domain] Cd Length: 95 Bit Score: 49.53 E-value: 3.58e-07

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  507 PRMLSP---RNQLIRVILYNRTRLDCPFFGSPIPTLRWFKNGQ---GSNLDGGnYHVYENG-SLEIKMIRKEDQGIYTCV 579
Cdd:cd05729      1 PRFTDTekmEEREHALPAANKVRLECGAGGNPMPNITWLKDGKefkKEHRIGG-TKVEEKGwSLIIERAIPRDKGKYTCI 79

                           90
                   ....*....|....*.
gi 2217265341  580 ATNILGKAENQVRLEV 595
Cdd:cd05729     80 VENEYGSINHTYDVDV 95

First immunoglobulin (Ig)-like domain of fibroblast growth factor receptor (FGFR); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of fibroblast growth factor receptor (FGFR). Fibroblast growth factors (FGFs) participate in morphogenesis, development, angiogenesis, and wound healing. These FGF-stimulated processes are mediated by four FGFR tyrosine kinases (FGRF1-4). FGFRs are comprised of an extracellular portion consisting of three Ig-like domains, a transmembrane helix, and a cytoplasmic portion having protein tyrosine kinase activity. The highly conserved Ig-like domains 2 and 3, and the linker region between D2 and D3 define a general binding site for all FGFs.

Pssm-ID: 409362 Cd Length: 94 Bit Score: 49.51 E-value: 4.09e-07

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  598 PTRIYRMPEDQVARRGTTVQLECRVKHDPSlklTVSWLKDDEPLYIGNRMKKEDDSLTIFGVAERDQGSYTCVASTELDQ 677
Cdd:cd04973      9 PTYQISEVESYSAHPGDLLQLRCRLRDDVQ---SINWTKDGVQLGENNRTRITGEEVQIKDAVPRDSGLYACVTSSPSGS 85


                   .
gi 2217265341  678 D 678
Cdd:cd04973     86 D 86

Immunoglobulin (Ig)-like domain of myotilin, palladin, and myopalladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain in myotilin, palladin, and myopalladin. Myotilin, palladin, and myopalladin function as scaffolds that regulate actin organization. Myotilin and myopalladin are most abundant in skeletal and cardiac muscle; palladin is ubiquitously expressed in the organs of developing vertebrates and plays a key role in cellular morphogenesis. The three family members each interact with specific molecular partners with all three binding to alpha-actinin; In addition, palladin also binds to vasodilator-stimulated phosphoprotein (VASP) and ezrin, myotilin binds to filamin and actin, and myopalladin also binds to nebulin and cardiac ankyrin repeat protein (CARP). This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409405 [Multi-domain] Cd Length: 91 Bit Score: 49.03 E-value: 4.67e-07

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  321 PSFMYPQGtasSQMVLRGMDLLLECIASGVPTPDIAWYKKGGDL-PSDKAKF---ENFNKALRITNVSEEDSGEYFCLAS 396
Cdd:cd05744      1 PHFLQAPG---DLEVQEGRLCRFDCKVSGLPTPDLFWQLNGKPVrPDSAHKMlvrENGRHSLIIEPVTKRDAGIYTCIAR 77


                   ....
gi 2217265341  397 NKMG 400
Cdd:cd05744     78 NRAG 81

Second Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409564 [Multi-domain] Cd Length: 91 Bit Score: 49.12 E-value: 5.09e-07

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  506 PPRMLS-PRNQLIRVilYNRTRLDCPFFGSPIPTLRWFKNGQ--GSNLDggnYHVYENGSLEIKMIRK---EDQGIYTCV 579
Cdd:cd20972      1 PPQFIQkLRSQEVAE--GSKVRLECRVTGNPTPVVRWFCEGKelQNSPD---IQIHQEGDLHSLIIAEafeEDTGRYSCL 75

                           90
                   ....*....|....*.
gi 2217265341  580 ATNILGKAENQVRLEV 595
Cdd:cd20972     76 ATNSVGSDTTSAEIFV 91

Immunoglobulin (Ig)-like domain found in Perlecan and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain found in Perlecan. Perlecan is a large multi-domain heparin sulfate proteoglycan, important in tissue development and organogenesis. Perlecan can be represented as 5 major portions; its fourth major portion (domain IV) is a tandem repeat of immunoglobulin-like domains (Ig2-Ig15) which can vary in size due to alternative splicing. Perlecan binds many cellular and extracellular ligands. Its domain IV region has many binding sites. Some of these have been mapped at the level of individual Ig-like domains, including a site restricted to the Ig5 domain for heparin/sulfatide, a site restricted to the Ig3 domain for nidogen-1 and nidogen-2, a site restricted to Ig4-5 for fibronectin, and sites restricted to Ig2 and to Ig13-15 for fibulin-2. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409412 Cd Length: 85 Bit Score: 48.71 E-value: 5.23e-07

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217265341  331 SSQMVLRGMDLLLECIA-SGVPTPDIAWYKKGGDLPSDKakfENFNKALRITNVSEEDSGEYFCLASN 397
Cdd:cd05754      9 RSQEVRPGADVSFICRAkSKSPAYTLVWTRVNGTLPSRA---MDFNGILTIRNVQLSDAGTYVCTGSN 73

Immunoglobulin (Ig)-like ectodomain of the LRIG1 (Leucine-rich Repeats And Immunoglobulin-like Domains Protein 1) and similar proteins; member of the I-set of IgSF domains; The members here are composed of subgroup of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. The ectodomain of LRIG1 has two distinct regions: the proposed 15 LRRs and three Ig-like domains closer to the membrane. LRIG1 has been reported to interact with many receptor tyrosine kinases, GDNF/c-Ret, E-cadherin, JAK/STAT, c-Met, and the EGFR family signaling systems. Immunoglobulin Superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The structure of the LRIG1 extracellular Ig domain lacks a C" strand and thus is better described as a member of the I-set of IgSF domains.

Pssm-ID: 409420 [Multi-domain] Cd Length: 91 Bit Score: 48.38 E-value: 7.93e-07

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  603 RMPEDQVARRGTTVQLECRVKHDPSLKltVSWLKD---DEPLYIGNRMK--KEDDSLTIFGVAERDQGSYTCVASTELDQ 677
Cdd:cd05763      4 KTPHDITIRAGSTARLECAATGHPTPQ--IAWQKDggtDFPAARERRMHvmPEDDVFFIVDVKIEDTGVYSCTAQNSAGS 81

                           90
                   ....*....|
gi 2217265341  678 DLAKAYLTVL 687
Cdd:cd05763     82 ISANATLTVL 91

Fourth immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the fourth immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted, and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143223 Cd Length: 69 Bit Score: 47.56 E-value: 8.14e-07

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217265341  526 RLDCPFFGSPIPTLRWFKNGQGSNlDGGNYHVYENGSLEIKMIRKEDQGIYTCVATNILGKAENQVRL 593
Cdd:cd05746      2 QIPCSAQGDPEPTITWNKDGVQVT-ESGKFHISPEGYLAIRDVGVADQGRYECVARNTIGYASVSMVL 68

Fibronectin type III domain;

Pssm-ID: 394996 [Multi-domain] Cd Length: 85 Bit Score: 48.18 E-value: 8.71e-07

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  905 APTEVKVRVMNSTAISLQWNRvySDTVQGQLREYRAYYWRESSLLKNLWVSQKRQQASFpgdrlrgVVSRLFPYSNYKLE 984
Cdd:pfam00041    2 APSNLTVTDVTSTSLTVSWTP--PPDGNGPITGYEVEYRPKNSGEPWNEITVPGTTTSV-------TLTGLKPGTEYEVR 72

                           90
                   ....*....|...
gi 2217265341  985 MVVVNGRGDGPRS 997
Cdd:pfam00041   73 VQAVNGGGEGPPS 85

Seventh immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the seventh immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409546 [Multi-domain] Cd Length: 96 Bit Score: 48.46 E-value: 8.82e-07

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  506 PPR-MLSPRNqlIRVILYNRTRLDCPFFGSPIPTLRWfKNGQGSN-------LDGGNYHVYENGSLEIKMIRKEDQGIYT 577
Cdd:cd20954      1 PPRwIVEPVD--ANVAAGQDVMLHCQADGFPTPTVTW-KKATGSTpgeykdlLYDPNVRILPNGTLVFGHVQKENEGHYL 77


                   ....*...
gi 2217265341  578 CVATNILG 585
Cdd:cd20954     78 CEAKNGIG 85

Fibronectin type III domain;

Pssm-ID: 394996 [Multi-domain] Cd Length: 85 Bit Score: 47.79 E-value: 1.03e-06

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217265341 1198 WNVTVLP-NSKWANITWKHNF---GPGTDFVVEYIDSNHT--KKTVPVKAQAQPIQLTDLYPGMTYTLRVYSRDNEGIS 1270
Cdd:pfam00041    4 SNLTVTDvTSTSLTVSWTPPPdgnGPITGYEVEYRPKNSGepWNEITVPGTTTSVTLTGLKPGTEYEVRVQAVNGGGEG 82

agrin-responsive first immunoglobulin-like domains (Ig1) of the MuSK ectodomain; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domains (Ig1) of the Muscle-specific kinase (MuSK). MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409562 [Multi-domain] Cd Length: 92 Bit Score: 48.27 E-value: 1.04e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  605 PEDQVARRGTTVQLECRVKHDPslKLTVSWLKDD---EPLYIGNRMKKEDDSLTIFGVAERDQGSYTCVASTELDQDLAK 681
Cdd:cd20970      9 SFTVTAREGENATFMCRAEGSP--EPEISWTRNGnliIEFNTRYIVRENGTTLTIRNIRRSDMGIYLCIASNGVPGSVEK 86


                   ..
gi 2217265341  682 AY 683
Cdd:cd20970     87 RI 88

Fourth immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues, and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409388 Cd Length: 84 Bit Score: 47.96 E-value: 1.13e-06

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217265341  339 MDLLLECIASGVPTPDIAWYKKGGD-LPSDKAKFENfNKALRITNVSEEDSGEYFCLASNKMGSIR 403
Cdd:cd05723     13 MDIVFECEVTGKPTPTVKWVKNGDVvIPSDYFKIVK-EHNLQVLGLVKSDEGFYQCIAENDVGNAQ 77

Third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule 1 (NCAM-1); member of the I-set of IgSF domains; The members here are composed of the third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule (NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-non-NCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions) through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain.

Pssm-ID: 143207 [Multi-domain] Cd Length: 95 Bit Score: 48.00 E-value: 1.21e-06

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217265341  525 TRLDCPFFGSPIPTLRWFKNGQGSNLDGGNYHVYENGS-LEIKMIRKEDQGIYTCVATNILGKAENQVRLEV 595
Cdd:cd05730     21 VTLACDADGFPEPTMTWTKDGEPIESGEEKYSFNEDGSeMTILDVDKLDEAEYTCIAENKAGEQEAEIHLKV 92

IL-beta-binding protein; Provisional

Pssm-ID: 165149 [Multi-domain] Cd Length: 326 Bit Score: 51.94 E-value: 1.30e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  561 GSLEIKMIRKEDQGIYTCVATNILG-KAENQ---VRLEVKD----PTriYRMPEDQVARRGTTVQLECRVK-HDPSLKLT 631
Cdd:PHA02785   177 GIITIEDVRKNDAGYYTCVLKYIYGdKTYNVtriVKLEVRDriipPT--MQLPEGVVTSIGSNLTIACRVSlRPPTTDAD 254

                           90       100       110       120       130
                   ....*....|....*....|....*....|....*....|....*....|....*....
gi 2217265341  632 VSWL-------KDDEP----LYIGNRMKKED------DSLTIFGVAERDQGSYTCVAST 673
Cdd:PHA02785   255 VFWIsngmyyeEDDEDgdgrISVANKIYTTDkrrvitSRLNINPVKEEDATTFTCMAFT 313

Immunoglobulin domain of human Synaptic Adhesion-Like Molecule 5 (SALM5) and similar proteins; member of the I-set of IgSF domains; This group contains the immunoglobulin domain of human Synaptic Adhesion-Like Molecule 5 (SALM5) and similar proteins. The SALM (for synaptic adhesion-like molecules; also known as Lrfn for leucine-rich repeat and fibronectin type III domain containing) family of adhesion molecules consists of five known members: SALM1/Lrfn2, SALM2/Lrfn1, SALM3/Lrfn4, SALM4/Lrfn3, and SALM5/Lrfn5. SALMs share a similar domain structure, containing leucine-rich repeats (LRRs), an immunoglobulin (Ig) domain, and a fibronectin III (FNIII) domain, followed by a transmembrane domain and a C-terminal PDZ-binding motif. SALM5 is implicated in autism spectrum disorders (ASDs) and schizophrenia, induces presynaptic differentiation in contacting axons. SALM5 interacts with the Ig domains of LAR (Leukocyte common Antigen-Related) family receptor protein tyrosine phosphatases (LAR-RPTPs; LAR, PTPdelta, and PTPsigma). In addition, PTPdelta is implicated in ASDs, ADHD, bipolar disorder, and restless leg syndrome. Studies have shown that LAR-RPTPs are novel and splicing-dependent presynaptic ligands for SALM5, and that they mediate SALM5-dependent presynaptic differentiation. Furthermore, SALM5 maintains AMPA receptor (AMPAR)-mediated excitatory synaptic transmission through mechanisms involving the interaction of SALM5 with LAR-RPTPs. This group belongs to the I-set of immunoglobulin superfamily (IgSF) domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409421 [Multi-domain] Cd Length: 88 Bit Score: 47.86 E-value: 1.32e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  518 RVILYNRTRLDCPFFGSPIPTLRWFknGQGSNLDGGNYH--VYENGSLEIKMIRKEDQGIYTCVATNILGKAENQVRLEV 595
Cdd:cd05764     11 RVLEGQRATLRCKARGDPEPAIHWI--SPEGKLISNSSRtlVYDNGTLDILITTVKDTGAFTCIASNPAGEATARVELHI 88

Immunoglobulin I-set domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1); The members here are composed of the immunoglobulin I-set (IgI) domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1). Human Lingo-1 is a central nervous system-specific transmembrane glycoprotein also known as LERN-1, which functions as a negative regulator of neuronal survival, axonal regeneration, and oligodendrocyte differentiation and myelination. Lingo-1 is a key component of the Nogo receptor signaling complex (RTN4R/NGFR) in RhoA activation responsible for some inhibition of axonal regeneration by myelin-associated factors. The ligand-binding ectodomain of human Lingo-1 contains a bimodular, kinked structure composed of leucine-rich repeat (LRR) and immunoglobulin (Ig)-like modules. Diseases associated with Lingo-1 include mental retardation, autosomal recessive 64 and essential tremor. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the Lingo-1 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409561 Cd Length: 92 Bit Score: 47.77 E-value: 1.39e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  506 PPRMLSPRNQLIRVILYNRTRLDCPFFGSPIPTLRWFKNGQG--SNLDGGNYHVYENGSLEIKMIRKEDQGIYTCVATNI 583
Cdd:cd20969      1 RAAIRDRKAQQVFVDEGHTVQFVCRADGDPPPAILWLSPRKHlvSAKSNGRLTVFPDGTLEVRYAQVQDNGTYLCIAANA 80

                           90
                   ....*....|..
gi 2217265341  584 LGKAENQVRLEV 595
Cdd:cd20969     81 GGNDSMPAHLHV 92

Seventh immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the seventh immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409546 [Multi-domain] Cd Length: 96 Bit Score: 47.69 E-value: 1.44e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  129 IVDPRD-------NILIECEAKGNPAPSFHWTRNS-----RFFNIAKDPRVSMRRrSGTLVIDFRSggrpEEYEGEYQCF 196
Cdd:cd20954      5 IVEPVDanvaagqDVMLHCQADGFPTPTVTWKKATgstpgEYKDLLYDPNVRILP-NGTLVFGHVQ----KENEGHYLCE 79

                           90
                   ....*....|....*..
gi 2217265341  197 ARNKFGTALSNRIRLQV 213
Cdd:cd20954     80 AKNGIGSGLSKVIFLKV 96

Second immunoglobulin (Ig)-like domain of protein tyrosine kinase (PTK) 7; The members here are composed of the second immunoglobulin (Ig)-like domain in protein tyrosine kinase (PTK) 7, also known as CCK4. PTK7 is a subfamily of the receptor protein tyrosine kinase family, and is referred to as an RPTK-like molecule. RPTKs transduce extracellular signals across the cell membrane and play important roles in regulating cell proliferation, migration, and differentiation. PTK7 is organized as an extracellular portion having seven Ig-like domains, a single transmembrane region, and a cytoplasmic tyrosine kinase-like domain. PTK7 is considered a pseudokinase as it has several unusual residues in some of the highly conserved tyrosine kinase (TK) motifs; it is predicted to lack TK activity. PTK7 may function as a cell-adhesion molecule. PTK7 mRNA is expressed at high levels in placenta, melanocytes, liver, lung, pancreas, and kidney. PTK7 is overexpressed in several cancers, including melanoma and colon cancer lines.

Pssm-ID: 409417 Cd Length: 95 Bit Score: 47.62 E-value: 1.59e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  118 PTITKQSAKDHIVDPRDNILIECEAKGNPAPSFHWTRNSrffNIAKDPR----VSMRRRSGTLvidfRSGGrpEEYEGEY 193
Cdd:cd05760      1 PVVLKHPASAAEIQPSSRVTLRCHIDGHPRPTYQWFRDG---TPLSDGQgnysVSSKERTLTL----RSAG--PDDSGLY 71

                           90
                   ....*....|....*
gi 2217265341  194 QCFARNKFGTALSNR 208
Cdd:cd05760     72 YCCAHNAFGSVCSSQ 86

Fourth Ig domain of the neural cell adhesion molecule contactin-2, and similar domains; The members here are composed of the fourth Ig domain of the neural cell adhesion molecule contactin-2. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (also called TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. The first four Ig domains form the intermolecular binding fragment which arranges as a compact U-shaped module by contacts between Ig domains 1 and 4, and domains 2 and 3. It has been proposed that a linear zipper-like array forms, from contactin-2 molecules alternatively provided by the two apposed membranes.

Pssm-ID: 143205 [Multi-domain] Cd Length: 85 Bit Score: 47.59 E-value: 1.64e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  123 QSAKDHIVDPRDNILIECEAKGNPAPSFHWTRNSRffNIAKDPRVSMrrRSGTLVIDFRSggrpEEYEGEYQCFARNKFG 202
Cdd:cd05728      4 KVISDTEADIGSSLRWECKASGNPRPAYRWLKNGQ--PLASENRIEV--EAGDLRITKLS----LSDSGMYQCVAENKHG 75


                   ....*
gi 2217265341  203 TALSN 207
Cdd:cd05728     76 TIYAS 80

Second C-terminal immunoglobulin (Ig)-like domain of palladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of palladin. Palladin belongs to the palladin-myotilin-myopalladin family. Proteins belonging to this family contain multiple Ig-like domains and function as scaffolds, modulating actin cytoskeleton. Palladin binds to alpha-actinin ezrin, vasodilator-stimulated phosphoprotein VASP, SPIN90 (also known as DIP or mDia interacting protein), and Src. Palladin also binds F-actin directly, via its Ig3 domain. Palladin is expressed as several alternatively spliced isoforms, having various combinations of Ig-like domains, in a cell-type-specific manner. It has been suggested that palladin's different Ig-like domains may be specialized for distinct functions. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409582 Cd Length: 91 Bit Score: 47.79 E-value: 1.66e-06

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217265341  526 RLDCPFFGSPIPTLRWFKNGQGSNLDGGNYH-VYENG--SLEIKMIRKEDQGIYTCVATNILGkaENQVRLEV 595
Cdd:cd20990     19 RMDCKVSGLPTPDLSWQLDGKPIRPDSAHKMlVRENGvhSLIIEPVTSRDAGIYTCIATNRAG--QNSFNLEL 89

Immunoglobulin (Ig)-like domain of titin and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain found in titin-like proteins and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is a giant protein; depending on isoform composition, it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone. It appears to function similarly to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. Within the sarcomere, titin is also attached to or is associated with myosin binding protein C (MyBP-C). MyBP-C appears to contribute to the generation of passive tension by titin and like titin has repeated Ig-like and FN-III domains. Also included in this group are worm twitchin and insect projectin, thick filament proteins of invertebrate muscle which also have repeated Ig-like and FN-III domains.

Pssm-ID: 409406 [Multi-domain] Cd Length: 82 Bit Score: 47.20 E-value: 1.81e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  334 MVLRGMDLLLECIASGVPTPDIAWYKKGGDL-PSDKAKFENFNKA--LRITNVSEEDSGEYFCLASNKMGSIRHTISVRV 410
Cdd:cd05748      3 VVRAGESLRLDIPIKGRPTPTVTWSKDGQPLkETGRVQIETTASStsLVIKNAKRSDSGKYTLTLKNSAGEKSATINVKV 82

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409549 [Multi-domain] Cd Length: 88 Bit Score: 47.14 E-value: 2.33e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  605 PEDQVARRGTTVQLECRVKHDPSLklTVSWLKDDEPLYIGNRMK-KEDDSLTIFGVAERDQGSYTCVASTELDQDLAKAY 683
Cdd:cd20957      8 PPVQTVDFGRTAVFNCSVTGNPIH--TVLWMKDGKPLGHSSRVQiLSEDVLVIPSVKREDKGMYQCFVRNDGDSAQATAE 85


                   .
gi 2217265341  684 L 684
Cdd:cd20957     86 L 86

First immunoglobulin (Ig) domain of contactin-5; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-5. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains, anchored to the membrane by glycosylphosphatidylinositol. The different contactins show different expression patterns in the central nervous system. In rats, a lack of contactin-5 (NB-2) results in an impairment of the neuronal activity in the auditory system. Contactin-5 is expressed specifically in the postnatal nervous system, peaking at about 3 weeks postnatal. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala; lower levels of expression have been detected in the corpus callosum, caudate nucleus, and spinal cord. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409435 Cd Length: 96 Bit Score: 47.24 E-value: 2.43e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  414 PYWLDEPKNLILAPGEDGRLV---CRANGNPKPTVQWMVNGEPLQSAPPNPNREVAGDTIIFRDTQISSRAVYQCNTSNE 490
Cdd:cd05848      2 PVFVQEPDDAIFPTDSDEKKVilnCEARGNPVPTYRWLRNGTEIDTESDYRYSLIDGNLIISNPSEVKDSGRYQCLATNS 81


                   ....*.
gi 2217265341  491 HGYLLA 496
Cdd:cd05848     82 IGSILS 87

C5 immunoglobulin (Ig) domain of cardiac myosin binding protein C (MyBP-C); The members here are composed of the C5 immunoglobulin (Ig) domain of cardiac myosin binding protein C (MyBP-C). MyBP-C consists of repeated domains, Ig and fibronectin type 3, and various linkers. Three isoforms of MYBP-C exist: slow-skeletal (ssMyBP-C), fast-skeletal (fsMyBP-C), and cardiac (cMyBP-C). cMYBP-C has insertions between and inside domains and an additional cardiac-specific Ig domain at the N-terminus. For cMYBP_C an interaction has been demonstrated between this C5 domain and the Ig C8 domain.

Pssm-ID: 409475 Cd Length: 86 Bit Score: 46.76 E-value: 2.66e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  517 IRVILYNRTRLDCPFFGSPIPTLRWFKNGQGSNLDGGNYHV---YENGSLEIKMIRKEDQGIYTCVATNILGkaENQVRL 593
Cdd:cd05894      5 IVVVAGNKLRLDVPISGEPAPTVTWSRGDKAFTATEGRVRVesyKDLSSFVIEGAEREDEGVYTITVTNPVG--EDHASL 82


                   ...
gi 2217265341  594 EVK 596
Cdd:cd05894     83 FVK 85

Second C-terminal immunoglobulin (Ig)-like domain of palladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of palladin. Palladin belongs to the palladin-myotilin-myopalladin family. Proteins belonging to this family contain multiple Ig-like domains and function as scaffolds, modulating actin cytoskeleton. Palladin binds to alpha-actinin ezrin, vasodilator-stimulated phosphoprotein VASP, SPIN90 (also known as DIP or mDia interacting protein), and Src. Palladin also binds F-actin directly, via its Ig3 domain. Palladin is expressed as several alternatively spliced isoforms, having various combinations of Ig-like domains, in a cell-type-specific manner. It has been suggested that palladin's different Ig-like domains may be specialized for distinct functions. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409582 Cd Length: 91 Bit Score: 47.02 E-value: 2.87e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  321 PSFMYPQGTASSQmvlRGMDLLLECIASGVPTPDIAWYKKGGDLPSDKAK----FENFNKALRITNVSEEDSGEYFCLAS 396
Cdd:cd20990      1 PHFLQAPGDLTVQ---EGKLCRMDCKVSGLPTPDLSWQLDGKPIRPDSAHkmlvRENGVHSLIIEPVTSRDAGIYTCIAT 77


                   ....
gi 2217265341  397 NKMG 400
Cdd:cd20990     78 NRAG 81

Fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related); The members here are composed of the fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related). These proteins belong to the L1 subfamily of cell adhesion molecules (CAMs) and are comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. These molecules are primarily expressed in the nervous system. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth.

Pssm-ID: 409367 [Multi-domain] Cd Length: 89 Bit Score: 46.67 E-value: 2.96e-06

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2217265341  331 SSQMVLRGMDLLLECIASGVPTPDIAWYKKG---GDLPSDKAKFENfNKALRITNVSEEDSGEYFCLASNKMGSI 402
Cdd:cd04978      7 PSLVLSPGETGELICEAEGNPQPTITWRLNGvpiEPAPEDMRRTVD-GRTLIFSNLQPNDTAVYQCNASNVHGYL 80

Immunoglobulin (Ig)-like domain in neuregulins; The members here are composed of the immunoglobulin (Ig)-like domain in neuregulins (NRGs). NRGs are signaling molecules which participate in cell-cell interactions in the nervous system, breast, heart, and other organ systems, and are implicated in the pathology of diseases including schizophrenia, multiple sclerosis, and breast cancer. There are four members of the neuregulin gene family (NRG-1, NRG-2, NRG-3, and NRG-4). The NRG-1 protein, binds to and activates the tyrosine kinases receptors ErbB3 and ErbB4, initiating signaling cascades. The other NRGs proteins bind one or the other or both of these ErbBs. NRG-1 has multiple functions: in the brain it regulates various processes such as radial glia formation and neuronal migration, dendritic development, and expression of neurotransmitters receptors, while in the peripheral nervous system NRG-1 regulates processes such as target cell differentiation, and Schwann cell survival. There are many NRG-1 isoforms which arise from the alternative splicing of mRNA. Less is known of the functions of the other NRGs. NRG-2 and NRG-3 are expressed predominantly in the nervous system. NRG-2 is expressed by motor neurons and terminal Schwann cells, and is concentrated near synaptic sites and may be a signal that regulates synaptic differentiation. NRG-4 has been shown to direct pancreatic islet cell development towards the delta-cell lineage.

Pssm-ID: 409408 [Multi-domain] Cd Length: 92 Bit Score: 46.74 E-value: 3.03e-06

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217265341  533 GSPIPTLRWFKNGQGSNLDGGNYHVYENGS----LEIKMIRKEDQGIYTCVATNILGKAENQVRLEV 595
Cdd:cd05750     26 ENPSPRYRWFKDGKELNRKRPKNIKIRNKKknseLQINKAKLEDSGEYTCVVENILGKDTVTGNVTV 92

Third immunoglobulin (Ig) domain of contactin-1; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 143259 Cd Length: 88 Bit Score: 46.55 E-value: 3.91e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  517 IRVILYNRTRLDCPFFGSPIPTLRWFKNGQGSNldgGNYHVYENGS-LEIKMIRKEDQGIYTCVATNILGKAENQVRLEV 595
Cdd:cd05851     11 TYALKGQNVTLECFALGNPVPVIRWRKILEPMP---ATAEISMSGAvLKIFNIQPEDEGTYECEAENIKGKDKHQARVYV 87


                   .
gi 2217265341  596 K 596
Cdd:cd05851     88 Q 88

Immunoglobulin I-set domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1); The members here are composed of the immunoglobulin I-set (IgI) domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1). Human Lingo-1 is a central nervous system-specific transmembrane glycoprotein also known as LERN-1, which functions as a negative regulator of neuronal survival, axonal regeneration, and oligodendrocyte differentiation and myelination. Lingo-1 is a key component of the Nogo receptor signaling complex (RTN4R/NGFR) in RhoA activation responsible for some inhibition of axonal regeneration by myelin-associated factors. The ligand-binding ectodomain of human Lingo-1 contains a bimodular, kinked structure composed of leucine-rich repeat (LRR) and immunoglobulin (Ig)-like modules. Diseases associated with Lingo-1 include mental retardation, autosomal recessive 64 and essential tremor. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the Lingo-1 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409561 Cd Length: 92 Bit Score: 46.61 E-value: 3.99e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  411 KAAPYWLDEPKNLILapgedgrlVCRANGNPKPTVQWMVNGEPLQSAPPNPN-REVAGDTIIFRDTQISSRAVYQCNTSN 489
Cdd:cd20969      8 KAQQVFVDEGHTVQF--------VCRADGDPPPAILWLSPRKHLVSAKSNGRlTVFPDGTLEVRYAQVQDNGTYLCIAAN 79


                   ...
gi 2217265341  490 EHG 492
Cdd:cd20969     80 AGG 82

Third immunoglobulin (Ig) domain of contactin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409357 [Multi-domain] Cd Length: 88 Bit Score: 46.39 E-value: 4.06e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  598 PTRIYRMPEDQVARRGTTVQLECRVKHDPSLklTVSWLKDDEPLYIGNRMKKEDDSLTIFGVAERDQGSYTCVASTELDQ 677
Cdd:cd04968      1 PSIKVRFPADTYALKGQTVTLECFALGNPVP--QIKWRKVDGSPSSQWEITTSEPVLEIPNVQFEDEGTYECEAENSRGK 78


                   ....*....
gi 2217265341  678 DLAKAYLTV 686
Cdd:cd04968     79 DTVQGRIIV 87

Fourth Ig-like domain from smooth muscle myosin light chain kinase and similar domains ; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain from smooth muscle myosin light chain kinase (MYLK) and similar domains. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of this group shows that the fourth Ig-like domain from myosin light chain kinase lacks this strand and thus belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409568 [Multi-domain] Cd Length: 90 Bit Score: 46.47 E-value: 4.10e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  117 PPTITKQSAKDHIVDPRDNILiECEAKGNPAPSFHWTRNSRFFNIAKDpRVSMRRRSGTLVIdfrSGGRPEEYeGEYQCF 196
Cdd:cd20976      1 APSFSSVPKDLEAVEGQDFVA-QCSARGKPVPRITWIRNAQPLQYAAD-RSTCEAGVGELHI---QDVLPEDH-GTYTCL 74


                   ....*...
gi 2217265341  197 ARNKFGTA 204
Cdd:cd20976     75 AKNAAGQV 82

immunoglobulin-like domain of telokin and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin (Ig) domain in telokin, the C-terminal domain of myosin light chain kinase which is identical to telokin, and similar proteins. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the telokin Ig domain lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409565 [Multi-domain] Cd Length: 88 Bit Score: 46.41 E-value: 4.18e-06

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217265341  526 RLDCPFFGSPIPTLRWFKNGQG---SNLDGGNYHVYENGSLEIKMIRKEDQGIYTCVATNILGKAENQVRLEV 595
Cdd:cd20973     16 RFDCKVEGYPDPEVKWMKDDNPiveSRRFQIDQDEDGLCSLIISDVCGDDSGKYTCKAVNSLGEATCSAELTV 88

Fifth immunoglobulin (Ig) domain of contactin; The members here are composed of the fifth immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409358 [Multi-domain] Cd Length: 89 Bit Score: 46.30 E-value: 4.30e-06

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217265341  609 VARRGTTVQLECRVKHDPslKLTVSWLKDDEPLYIGNRMKKEDD-SLTIFGVAERDQGSYTCVASTELDQDLAKAYLTV 686
Cdd:cd04969     13 LAAKGGDVIIECKPKASP--KPTISWSKGTELLTNSSRICILPDgSLKIKNVTKSDEGKYTCFAVNFFGKANSTGSLSV 89

Fibronectin type 3 domain; One of three types of internal repeats found in the plasma protein fibronectin. Its tenth fibronectin type III repeat contains an RGD cell recognition sequence in a flexible loop between 2 strands. Approximately 2% of all animal proteins contain the FN3 repeat; including extracellular and intracellular proteins, membrane spanning cytokine receptors, growth hormone receptors, tyrosine phosphatase receptors, and adhesion molecules. FN3-like domains are also found in bacterial glycosyl hydrolases.

Pssm-ID: 238020 [Multi-domain] Cd Length: 93 Bit Score: 46.34 E-value: 4.33e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341 1199 NVTVLPNSK-WANITWK---HNFGPGTDFVVEYIDSNHTK-KTVPVKAQAQP-IQLTDLYPGMTYTLRVYSRDNEGIS-- 1270
Cdd:cd00063      6 NLRVTDVTStSVTLSWTppeDDGGPITGYVVEYREKGSGDwKEVEVTPGSETsYTLTGLKPGTEYEFRVRAVNGGGESpp 85


                   ....*...
gi 2217265341 1271 STVITFMT 1278
Cdd:cd00063     86 SESVTVTT 93

Fibronectin type III domain;

Pssm-ID: 394996 [Multi-domain] Cd Length: 85 Bit Score: 46.25 E-value: 4.41e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  806 SNPGDVKGEGTRKNNMEITWTPmnATSAFGPNLRYIVKWRRRETREAWNNVTVWGSRY---VVGQTPvYVPYEIRVQAEN 882
Cdd:pfam00041    1 SAPSNLTVTDVTSTSLTVSWTP--PPDGNGPITGYEVEYRPKNSGEPWNEITVPGTTTsvtLTGLKP-GTEYEVRVQAVN 77


                   ....*..
gi 2217265341  883 DFGKGPE 889
Cdd:pfam00041   78 GGGEGPP 84

First immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409387 Cd Length: 97 Bit Score: 46.32 E-value: 4.71e-06

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217265341  527 LDCPFFGSPIPTLRWFKNGQGSNLDGG-NYHVYENGSLEIKMI-----RKEDQGIYTCVATN 582
Cdd:cd05722     21 LNCSAESDPPPKIEWKKDGVLLNLVSDeRRQQLPNGSLLITSVvhskhNKPDEGFYQCVAQN 82

Immunoglobulin (Ig)-like domain of the human basement membrane heparan sulfate proteoglycan perlecan and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain of the human basement membrane heparan sulfate proteoglycan perlecan, also known as HSPG2, and similar proteins. Perlecan consists of five domains: domain I has three putative heparan sulfate attachment sites, domain II has four LDL receptor-like repeats, and one Ig-like repeat, domain III resembles the short arm of laminin chains, domain IV has multiple Ig-like repeats (21 repeats in human perlecan), and domain V resembles the globular G domain of the laminin A chain and internal repeats of EGF. Perlecan may participate in a variety of biological functions including cell binding, LDL-metabolism, basement membrane assembly and selective permeability, calcium binding, and growth- and neurite-promoting activities.

Pssm-ID: 143220 Cd Length: 78 Bit Score: 45.94 E-value: 5.07e-06

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217265341  338 GMDLLLECIASGVPTPDIAWYKKGGDLPSDKA---KFENFNKALRITNVSEEDSGEYFCLASNKMGSI 402
Cdd:cd05743      1 GETVEFTCVATGVPTPIINWRLNWGHVPDSARvsiTSEGGYGTLTIRDVKESDQGAYTCEAINTRGMV 68

First Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409566 [Multi-domain] Cd Length: 93 Bit Score: 46.19 E-value: 5.31e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  331 SSQMVLRGMDLLLECIASGVPTPDIAWYKKG-----GDLPSDKAKFENFNKALRITNVSEEDSGEYFCLASNKMGSIRHT 405
Cdd:cd20974      8 QSVVVLEGSTATFEAHVSGKPVPEVSWFRDGqvistSTLPGVQISFSDGRAKLSIPAVTKANSGRYSLTATNGSGQATST 87


                   ....*.
gi 2217265341  406 ISVRVK 411
Cdd:cd20974     88 AELLVL 93

Second Ig-like domain of Junctional adhesion molecule-1 (JAM1); a member of the I-set of IgSF domains; The members here are composed of the second Ig-like domain of Junctional adhesion molecule-1 (JAM1). JAM1 is an immunoglobulin superfamily (IgSF) protein with two Ig-like domains in its extracellular region; it plays a role in the formation of endothelial and epithelial tight junction and acts as a receptor for mammalian reovirus sigma-1. The IgSF is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The second Ig-like domain of JAM1 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, the A strand of the I-set is discontinuous but lacks a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors.

Pssm-ID: 409542 Cd Length: 97 Bit Score: 46.16 E-value: 5.72e-06

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217265341  349 GVPTPDIAWYKKGGDLPSDKAKFENFNKA----------LRITNVSEEDSGEYFCLASNKMGSIRHTISVRVKA 412
Cdd:cd20950     24 GSPPSEYTWFKDGVVMPTNPKSTRAFSNSsysldpttgeLVFDPLSASDTGEYSCEARNGYGTPMRSNAVRMEA 97

Immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM) and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains NrCAM [Ng(neuronglia)CAM-related cell adhesion molecule], which is primarily expressed in the nervous system, and human neurofascin. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lacks a C" strand.

Pssm-ID: 409396 [Multi-domain] Cd Length: 94 Bit Score: 46.25 E-value: 5.86e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  420 PKNLILAPGEDGRLVCRANGNPKPTVQWMVNGEP--LQSAPPNPNREVAGDTII-FRDTQISS-RAVYQCNTSNEHGYLL 495
Cdd:cd05733      8 PKDYIVDPRDNITIKCEAKGNPQPTFRWTKDGKFfdPAKDPRVSMRRRSGTLVIdNHNGGPEDyQGEYQCYASNELGTAI 87


                   ..
gi 2217265341  496 AN 497
Cdd:cd05733     88 SN 89

Fibronectin type 3 domain; One of three types of internal repeat within the plasma protein, fibronectin. The tenth fibronectin type III repeat contains a RGD cell recognition sequence in a flexible loop between 2 strands. Type III modules are present in both extracellular and intracellular proteins.

Pssm-ID: 214495 [Multi-domain] Cd Length: 83 Bit Score: 45.68 E-value: 6.89e-06

                            10        20        30        40        50        60        70        80
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341   905 APTEVKVRVMNSTAISLQWNRVYSDTVQGQLREYRAYYWRESSLLKNLWVSQKRQQASFPGdrlrgvvsrLFPYSNYKLE 984
Cdd:smart00060    3 PPSNLRVTDVTSTSVTLSWEPPPDDGITGYIVGYRVEYREEGSEWKEVNVTPSSTSYTLTG---------LKPGTEYEFR 73

                            90
                    ....*....|
gi 2217265341   985 MVVVNGRGDG 994
Cdd:smart00060   74 VRAVNGAGEG 83

C-terminal immunoglobulin (Ig)-like domain of myomesin and M-protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of myomesin and M-protein (also known as myomesin-2). Myomesin and M-protein are both structural proteins localized to the M-band, a transverse structure in the center of the sarcomere, and are candidates for M-band bridges. Both proteins are modular, consisting mainly of repetitive Ig-like and fibronectin type III (FnIII) domains. Myomesin is expressed in all types of vertebrate striated muscle; M-protein has a muscle-type specific expression pattern. Myomesin is present in both slow and fast fibers; M-protein is present only in fast fibers. It has been suggested that myomesin acts as a molecular spring with alternative splicing as a means of modifying its elasticity.

Pssm-ID: 319300 Cd Length: 92 Bit Score: 45.66 E-value: 7.11e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  335 VLRGMDLLLECIASGVPTPDIAWYKKGGDLpsdkAKFENFNKALR--------ITNVSEEDSGEYFCLASNKMGS--IRH 404
Cdd:cd05737     13 IMEGKTLNLTCNVWGDPPPEVSWLKNDQAL----AFLDHCNLKVEagrtvyftINGVSSEDSGKYGLVVKNKYGSetSDV 88


                   ....
gi 2217265341  405 TISV 408
Cdd:cd05737     89 TVSV 92

Third immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the third immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The third Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules, including vascular (VCAM), intercellular (ICAM), neural (NCAM) and mucosal addressin (MADCAM) cell adhesion molecules, as well as junction adhesion molecules (JAM).

Pssm-ID: 409569 Cd Length: 93 Bit Score: 45.84 E-value: 7.27e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  326 PQGTASSQMVLRGMDLLLECIASGVPTPDIAWYKKGGDL---PSDKAKFENFN--KALRITNVSEEDSGEYFCLASNKMG 400
Cdd:cd20977      3 PQYVSKDMMAKAGDVTMIYCMYGSNPTAHPNYFKNGKDVngnPEDRITRHNRTsgKRLLFKTTLPEDEGVYTCEVDNGVG 82

                           90
                   ....*....|.
gi 2217265341  401 -SIRHTISVRV 410
Cdd:cd20977     83 kPQKHSLKLTV 93

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 45.71 E-value: 7.80e-06

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  118 PTITKQSaKDHIVDPRDNILIECEAKGNPAPSFHWTRNSRffNIAKDPRVSMRRRSG--TLVIDfrsgGRPEEYEGEYQC 195
Cdd:pfam07679    1 PKFTQKP-KDVEVQEGESARFTCTVTGTPDPEVSWFKDGQ--PLRSSDRFKVTYEGGtyTLTIS----NVQPDDSGKYTC 73

                           90
                   ....*....|....*...
gi 2217265341  196 FARNKFGTAlSNRIRLQV 213
Cdd:pfam07679   74 VATNSAGEA-EASAELTV 90

Fourth immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues, and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409388 Cd Length: 84 Bit Score: 45.27 E-value: 9.24e-06

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217265341  527 LDCPFFGSPIPTLRWFKNGQGSnLDGGNYHVYENGSLEIKMIRKEDQGIYTCVATNILGKAENQVRL 593
Cdd:cd05723     17 FECEVTGKPTPTVKWVKNGDVV-IPSDYFKIVKEHNLQVLGLVKSDEGFYQCIAENDVGNAQASAQL 82

Fourth Ig domain of the neural cell adhesion molecule contactin-2, and similar domains; The members here are composed of the fourth Ig domain of the neural cell adhesion molecule contactin-2. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (also called TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. The first four Ig domains form the intermolecular binding fragment which arranges as a compact U-shaped module by contacts between Ig domains 1 and 4, and domains 2 and 3. It has been proposed that a linear zipper-like array forms, from contactin-2 molecules alternatively provided by the two apposed membranes.

Pssm-ID: 143205 [Multi-domain] Cd Length: 85 Bit Score: 44.90 E-value: 1.13e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  605 PEDQVARRGTTVQLECRVKHDPslKLTVSWLKDDEPLYIGNRMKKEDDSLTIFGVAERDQGSYTCVASTELDQDLAKAYL 684
Cdd:cd05728      6 ISDTEADIGSSLRWECKASGNP--RPAYRWLKNGQPLASENRIEVEAGDLRITKLSLSDSGMYQCVAENKHGTIYASAEL 83


                   ..
gi 2217265341  685 TV 686
Cdd:cd05728     84 AV 85

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

Pssm-ID: 409544 [Multi-domain] Cd Length: 87 Bit Score: 45.18 E-value: 1.18e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  120 ITKQSAKDHIVDPRDNILIECEAKGNPAPSFHWTRNSRFFnIAKDPRVSMrRRSGTLVIdfrSGGRPEEyEGEYQCFARN 199
Cdd:cd20952      1 IILQGPQNQTVAVGGTVVLNCQATGEPVPTISWLKDGVPL-LGKDERITT-LENGSLQI---KGAEKSD-TGEYTCVALN 74


                   ....*.
gi 2217265341  200 KFGTAL 205
Cdd:cd20952     75 LSGEAT 80

Immunoglobulin (Ig)-like ectodomain of the LRIG1 (Leucine-rich Repeats And Immunoglobulin-like Domains Protein 1) and similar proteins; member of the I-set of IgSF domains; The members here are composed of subgroup of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. The ectodomain of LRIG1 has two distinct regions: the proposed 15 LRRs and three Ig-like domains closer to the membrane. LRIG1 has been reported to interact with many receptor tyrosine kinases, GDNF/c-Ret, E-cadherin, JAK/STAT, c-Met, and the EGFR family signaling systems. Immunoglobulin Superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The structure of the LRIG1 extracellular Ig domain lacks a C" strand and thus is better described as a member of the I-set of IgSF domains.

Pssm-ID: 409420 [Multi-domain] Cd Length: 91 Bit Score: 44.92 E-value: 1.35e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  420 PKNLILAPGEDGRLVCRANGNPKPTVQWMVNGEPLQSAPPNPNREVAGDTIIF--RDTQISSRAVYQCNTSNEHGYLLAN 497
Cdd:cd05763      6 PHDITIRAGSTARLECAATGHPTPQIAWQKDGGTDFPAARERRMHVMPEDDVFfiVDVKIEDTGVYSCTAQNSAGSISAN 85


                   ....*.
gi 2217265341  498 AFVSVL 503
Cdd:cd05763     86 ATLTVL 91

Immunoglobulin (Ig)-like domain of myotilin, palladin, and myopalladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain in myotilin, palladin, and myopalladin. Myotilin, palladin, and myopalladin function as scaffolds that regulate actin organization. Myotilin and myopalladin are most abundant in skeletal and cardiac muscle; palladin is ubiquitously expressed in the organs of developing vertebrates and plays a key role in cellular morphogenesis. The three family members each interact with specific molecular partners with all three binding to alpha-actinin; In addition, palladin also binds to vasodilator-stimulated phosphoprotein (VASP) and ezrin, myotilin binds to filamin and actin, and myopalladin also binds to nebulin and cardiac ankyrin repeat protein (CARP). This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409405 [Multi-domain] Cd Length: 91 Bit Score: 44.41 E-value: 1.87e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  414 PYWLDEPKNLILAPGEDGRLVCRANGNPKPTVQWMVNGEPLQ--SAPPNPNREVAGDTIIFRDTQISSRAVYQCNTSNEH 491
Cdd:cd05744      1 PHFLQAPGDLEVQEGRLCRFDCKVSGLPTPDLFWQLNGKPVRpdSAHKMLVRENGRHSLIIEPVTKRDAGIYTCIARNRA 80

                           90
                   ....*....|....
gi 2217265341  492 GyllANAFVSVLDV 505
Cdd:cd05744     81 G---ENSFNAELVV 91

Fourth immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The fourth Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409570 [Multi-domain] Cd Length: 88 Bit Score: 44.31 E-value: 1.90e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  118 PTITKQSAKDHIVDPRDNILIECEAKGNPAPSFHWTRNSRFFnIAKDPRVSMRRrsGTLVIdfrSGGRPEEyEGEYQCFA 197
Cdd:cd20978      1 PKFIQKPEKNVVVKGGQDVTLPCQVTGVPQPKITWLHNGKPL-QGPMERATVED--GTLTI---INVQPED-TGYYGCVA 73


                   ....*.
gi 2217265341  198 RNKFGT 203
Cdd:cd20978     74 TNEIGD 79

First immunoglobulin (Ig) domain of contactin-5; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-5. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains, anchored to the membrane by glycosylphosphatidylinositol. The different contactins show different expression patterns in the central nervous system. In rats, a lack of contactin-5 (NB-2) results in an impairment of the neuronal activity in the auditory system. Contactin-5 is expressed specifically in the postnatal nervous system, peaking at about 3 weeks postnatal. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala; lower levels of expression have been detected in the corpus callosum, caudate nucleus, and spinal cord. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409435 Cd Length: 96 Bit Score: 44.55 E-value: 1.98e-05

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2217265341  341 LLLECIASGVPTPDIAWYKKGG--DLPSDkAKFENFNKALRITNVSE-EDSGEYFCLASNKMGSI 402
Cdd:cd05848     22 VILNCEARGNPVPTYRWLRNGTeiDTESD-YRYSLIDGNLIISNPSEvKDSGRYQCLATNSIGSI 85

Third immunoglobulin (Ig)-like domain of the receptor protein tyrosine phosphatase (RPTP)-F (also known as LAR), type IIa; member of the I-set of IgSF domains; The members here are composed of the third immunoglobulin (Ig)-like domain found in the receptor protein tyrosine phosphatase (RPTP)-F, also known as LAR. LAR belongs to the RPTP type IIa subfamily. Members of this subfamily are cell adhesion molecule-like proteins involved in central nervous system (CNS) development. They have large extracellular portions comprised of multiple Ig-like domains and two to nine fibronectin type III (FNIII) domains and a cytoplasmic portion having two tandem phosphatase domains. Included in this group is Drosophila LAR (DLAR).

Pssm-ID: 409401 Cd Length: 82 Bit Score: 44.12 E-value: 1.98e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  331 SSQMVLRGMDLLLECIASGVPTPDIAWYKKGGDLPSDKAKFENFNkALRITNVSEedSGEYFCLASNKMGSIRHTISVRV 410
Cdd:cd05739      5 SNHEVMPGGSVNLTCVAVGAPMPYVKWMKGGEELTKEDEMPVGRN-VLELTNIYE--SANYTCVAISSLGMIEATAQVTV 81


                   .
gi 2217265341  411 K 411
Cdd:cd05739     82 K 82

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three IG-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans.

Pssm-ID: 409443 [Multi-domain] Cd Length: 95 Bit Score: 44.46 E-value: 2.08e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  414 PYWLDEP---KNLILAP-GEDGRLVCRANGNPKPTVQWMVNGEPLQsappnPNREVAG-------DTIIFRDTQISSRAV 482
Cdd:cd05857      1 PYWTNPEkmeKKLHAVPaANTVKFRCPAAGNPTPTMRWLKNGKEFK-----QEHRIGGykvrnqhWSLIMESVVPSDKGN 75

                           90
                   ....*....|
gi 2217265341  483 YQCNTSNEHG 492
Cdd:cd05857     76 YTCVVENEYG 85

Fibronectin type 3 domain; One of three types of internal repeat within the plasma protein, fibronectin. The tenth fibronectin type III repeat contains a RGD cell recognition sequence in a flexible loop between 2 strands. Type III modules are present in both extracellular and intracellular proteins.

Pssm-ID: 214495 [Multi-domain] Cd Length: 83 Bit Score: 44.14 E-value: 2.12e-05

                            10        20        30        40        50        60        70
                    ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217265341  1199 NVTVLPNSK-WANITWKH-NFGPGTDFVVEYI----DSNHTKKTVPVKAQAQPIQLTDLYPGMTYTLRVYSRDNEGIS 1270
Cdd:smart00060    6 NLRVTDVTStSVTLSWEPpPDDGITGYIVGYRveyrEEGSEWKEVNVTPSSTSYTLTGLKPGTEYEFRVRAVNGAGEG 83

First immunoglobulin (Ig)-like constant domain in Robo (roundabout) receptors, and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain in Roundabout (Robo) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit1, Slit2, Slit3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit1, Slit2,and Slit3 are expressed at the ventral midline. Robo3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site.

Pssm-ID: 409490 [Multi-domain] Cd Length: 99 Bit Score: 44.46 E-value: 2.42e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  600 RIYRMPEDQVARRGTTVQLECRVKHDPSlkLTVSWLKDDEPLYI------GNRMKKEDDSLTIFGV-----AERDQGSYT 668
Cdd:cd07693      2 RIVEHPSDLIVSKGDPATLNCKAEGRPT--PTIQWLKNGQPLETdkddprSHRIVLPSGSLFFLRVvhgrkGRSDEGVYV 79


                   ....*..
gi 2217265341  669 CVASTEL 675
Cdd:cd07693     80 CVAHNSL 86

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409549 [Multi-domain] Cd Length: 88 Bit Score: 44.06 E-value: 2.58e-05

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|....*...
gi 2217265341  527 LDCPFFGSPIPTLRWFKNGQ--GSNldgGNYHVYENGSLEIKMIRKEDQGIYTCVATN 582
Cdd:cd20957     21 FNCSVTGNPIHTVLWMKDGKplGHS---SRVQILSEDVLVIPSVKREDKGMYQCFVRN 75

First immunoglobulin (Ig)-like domain of hemolin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin (Ig)-like domain of hemolin and similar proteins. Hemolin, an insect immunoglobulin superfamily (IgSF) member containing four Ig-like domains, is a lipopolysaccharide-binding immune protein induced during bacterial infection. Hemolin shares significant sequence similarity with the first four Ig-like domains of the transmembrane cell adhesion molecules (CAMs) of the L1 family. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The first Ig-like domain of hemolin is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules, including vascular (VCAM), intercellular (ICAM), neural (NCAM) and mucosal addressin (MADCAM) cell adhesion molecules, as well as junction adhesion molecules (JAM).

Pssm-ID: 409571 Cd Length: 91 Bit Score: 44.10 E-value: 2.63e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217265341  138 IECEAKG-NPAPSFHWTRNSRFFNIAKDpRVSMRRRSGTLVidFRsggRPEEY-EGEYQCFARNKFGTALSNRIRLQ 212
Cdd:cd20979     20 LECVTEGgDQGVKYSWLKDGKSFNWQEH-NVAQRKDEGSLV--FL---KPQASdEGQYQCFAETPAGVASSRVISFR 90

Fourth Ig-like domain from smooth muscle myosin light chain kinase and similar domains ; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain from smooth muscle myosin light chain kinase (MYLK) and similar domains. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of this group shows that the fourth Ig-like domain from myosin light chain kinase lacks this strand and thus belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409568 [Multi-domain] Cd Length: 90 Bit Score: 44.16 E-value: 2.65e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  413 APYWLDEPKNLILAPGEDGRLVCRANGNPKPTVQWMVNGEPLQSAPPNPNREVAGDTIIFRDTQISSRAVYQCNTSNEHG 492
Cdd:cd20976      1 APSFSSVPKDLEAVEGQDFVAQCSARGKPVPRITWIRNAQPLQYAADRSTCEAGVGELHIQDVLPEDHGTYTCLAKNAAG 80

                           90
                   ....*....|
gi 2217265341  493 YLLANAFVSV 502
Cdd:cd20976     81 QVSCSAWVTV 90

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 44.11 E-value: 2.69e-05

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217265341  335 VLRGMDLLLECIAS-GVPTPDIAWYKKGGDLPSDKAKFENFNK----ALRITNVSEEDSGEYFCLASN 397
Cdd:pfam00047    8 VLEGDSATLTCSAStGSPGPDVTWSKEGGTLIESLKVKHDNGRttqsSLLISNVTKEDAGTYTCVVNN 75

First immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409387 Cd Length: 97 Bit Score: 44.39 E-value: 2.72e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2217265341  336 LRGMDLLLECIASGVPTPDIAWYKKGG--DLPSDKAKFENFNKALRITNV-----SEEDSGEYFCLASNK-MGSI 402
Cdd:cd05722     14 MRGGPVVLNCSAESDPPPKIEWKKDGVllNLVSDERRQQLPNGSLLITSVvhskhNKPDEGFYQCVAQNEsLGSI 88

Fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related); The members here are composed of the fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related). These proteins belong to the L1 subfamily of cell adhesion molecules (CAMs) and are comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. These molecules are primarily expressed in the nervous system. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth.

Pssm-ID: 409367 [Multi-domain] Cd Length: 89 Bit Score: 43.98 E-value: 2.85e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217265341  129 IVDPRDNILIECEAKGNPAPSFHWTRNSRFFNIAKdPRVSMRRRSGTLVIDFRSggrpEEYEGEYQCFARNKFGTALSN 207
Cdd:cd04978     10 VLSPGETGELICEAEGNPQPTITWRLNGVPIEPAP-EDMRRTVDGRTLIFSNLQ----PNDTAVYQCNASNVHGYLLAN 83

Immunoglobulin (Ig)-like domain of titin and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain found in titin-like proteins and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is a giant protein; depending on isoform composition, it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone. It appears to function similarly to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. Within the sarcomere, titin is also attached to or is associated with myosin binding protein C (MyBP-C). MyBP-C appears to contribute to the generation of passive tension by titin and like titin has repeated Ig-like and FN-III domains. Also included in this group are worm twitchin and insect projectin, thick filament proteins of invertebrate muscle which also have repeated Ig-like and FN-III domains.

Pssm-ID: 409406 [Multi-domain] Cd Length: 82 Bit Score: 43.73 E-value: 2.89e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217265341  526 RLDCPFFGSPIPTLRWFKNGQGSNLDG-GNYHVYE-NGSLEIKMIRKEDQGIYTCVATNILGKAENQVRLEV 595
Cdd:cd05748     11 RLDIPIKGRPTPTVTWSKDGQPLKETGrVQIETTAsSTSLVIKNAKRSDSGKYTLTLKNSAGEKSATINVKV 82

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM); The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains, five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM.

Pssm-ID: 409460 [Multi-domain] Cd Length: 83 Bit Score: 43.75 E-value: 2.93e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  609 VARRGTTVQLECRVKHDPSLklTVSWLKDDEPLyIGNRMKKE--DDSLTIFGVAERDQGSYTCVASTELDQDLAKAYLTV 686
Cdd:cd05876      6 VALRGQSLVLECIAEGLPTP--TVKWLRPSGPL-PPDRVKYQnhNKTLQLLNVGESDDGEYVCLAENSLGSARHAYYVTV 82

Immunoglobulin (Ig)-like domain found in neuregulin (NRG)-1; The members here are composed of the immunoglobulin (Ig)-like domain found in neuregulin (NRG)-1. There are many NRG-1 isoforms which arise from the alternative splicing of mRNA. NRG-1 belongs to the neuregulin gene family which is comprised of four genes. This group represents NRG-1. NRGs are signaling molecules which participate in cell-cell interactions in the nervous system, breast, and heart, and other organ systems, and are implicated in the pathology of diseases including schizophrenia, multiple sclerosis, and breast cancer. The NRG-1 protein binds to and activates the tyrosine kinases receptors ErbB3 and ErbB4, initiating signaling cascades. NRG-1 has multiple functions, for example, in the brain it regulates various processes such as radial glia formation and neuronal migration, dendritic development, and expression of neurotransmitters receptors in the peripheral nervous system NRG-1 regulates processes such as target cell differentiation, and Schwann cell survival.

Pssm-ID: 409476 Cd Length: 93 Bit Score: 43.83 E-value: 3.42e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  332 SQMVLRGMDLLLECIA-SGVPTPDIAWYKKGGDLpSDKAKFENFN-------KALRITNVSEEDSGEYFCLASNKMGSIR 403
Cdd:cd05895      8 SQEVAAGSKLVLRCETsSEYPSLRFKWFKNGKEI-NRKNKPENIKiqkkkkkSELRINKASLADSGEYMCKVSSKLGNDS 86


                   ....*..
gi 2217265341  404 HTISVRV 410
Cdd:cd05895     87 ASANVTI 93

Fifth immunoglobulin (Ig) domain of contactin-1; The members here are composed of the fifth immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409438 Cd Length: 89 Bit Score: 43.83 E-value: 3.50e-05

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217265341  604 MPEDQVARRGTTVQLECRVKHDPSLKLtvSWLKDDEPLYIGNRMKKEDD-SLTIFGVAERDQGSYTCVA 671
Cdd:cd05852      8 MKKKILAAKGGRVIIECKPKAAPKPKF--SWSKGTELLVNNSRISIWDDgSLEILNITKLDEGSYTCFA 74

Immunoglobulin (Ig)-like domain of human titin C terminus and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain from the C-terminus of human titin x and similar proteins. Titin (also called connectin) is a fibrous sarcomeric protein specifically found in vertebrate striated muscle. Titin is gigantic; depending on isoform composition it ranges from 2970 to 3700 kDa, and is of a length that spans half a sarcomere. Titin largely consists of multiple repeats of Ig-like and fibronectin type 3 (FN-III)-like domains. Titin connects the ends of myosin thick filaments to Z disks and extends along the thick filament to the H zone and appears to function similar to an elastic band, keeping the myosin filaments centered in the sarcomere during muscle contraction or stretching. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 143224 [Multi-domain] Cd Length: 92 Bit Score: 43.88 E-value: 3.94e-05

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|.
gi 2217265341  417 LDEPKNLILAPGEDGRLVCRANGNPKPTVQWMVNGEPLQSA 457
Cdd:cd05747      7 LTKPRSLTVSEGESARFSCDVDGEPAPTVTWMREGQIIVSS 47

Immunoglobulin (Ig)-like domain found in Perlecan and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain found in Perlecan. Perlecan is a large multi-domain heparin sulfate proteoglycan, important in tissue development and organogenesis. Perlecan can be represented as 5 major portions; its fourth major portion (domain IV) is a tandem repeat of immunoglobulin-like domains (Ig2-Ig15) which can vary in size due to alternative splicing. Perlecan binds many cellular and extracellular ligands. Its domain IV region has many binding sites. Some of these have been mapped at the level of individual Ig-like domains, including a site restricted to the Ig5 domain for heparin/sulfatide, a site restricted to the Ig3 domain for nidogen-1 and nidogen-2, a site restricted to Ig4-5 for fibronectin, and sites restricted to Ig2 and to Ig13-15 for fibulin-2. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409412 Cd Length: 85 Bit Score: 43.31 E-value: 3.94e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  605 PEDQVARRGTTVQLECRVKhDPSLKLTVSWLKDDEPLyiGNRMKKEDDSLTIFGVAERDQGSYTCVASTELDQDLAKAYL 684
Cdd:cd05754      8 PRSQEVRPGADVSFICRAK-SKSPAYTLVWTRVNGTL--PSRAMDFNGILTIRNVQLSDAGTYVCTGSNMLDTDEATATL 84

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 43.34 E-value: 4.18e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  604 MPEDQVARRGTTVQLECRVKHDPSLkLTVSWLKDD----EPLYIG-NRMKKEDDSLTIFGVAERDQGSYTCVASTELDQD 678
Cdd:pfam00047    2 APPTVTVLEGDSATLTCSASTGSPG-PDVTWSKEGgtliESLKVKhDNGRTTQSSLLISNVTKEDAGTYTCVVNNPGGSA 80

Immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM); The members here are composed of the immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM). DSCAM is a cell adhesion molecule expressed largely in the developing nervous system. The gene encoding DSCAM is located at human chromosome 21q22, the locus associated with the intellectual disability phenotype of Down Syndrome. DSCAM is predicted to be the largest member of the IG superfamily. It has been demonstrated that DSCAM can mediate cation-independent homophilic intercellular adhesion.

Pssm-ID: 409397 [Multi-domain] Cd Length: 97 Bit Score: 43.64 E-value: 4.18e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217265341  338 GMDLLLECIASGVPTPDIAW-YKKGGDLPSDKAKFEN-------FNKALRITNVSEEDSGEYFCLASNKMGS 401
Cdd:cd05734     16 GKAVVLNCSADGYPPPTIVWkHSKGSGVPQFQHIVPLngriqllSNGSLLIKHVLEEDSGYYLCKVSNDVGA 87

Second immunoglobulin (Ig)-like domain of a Follistatin-related protein 5, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in human Follistatin-related protein 5 (FSTL5) and a follistatin-like molecule encoded by the CNS-related Mahya gene. Mahya genes have been retained in certain Bilaterian branches during evolution. They are conserved in Hymenoptera and Deuterostomes, but are absent from other metazoan species such as fruit fly and nematode. Mahya proteins are secretory, with a follistatin-like domain (Kazal-type serine/threonine protease inhibitor domain and EF-hand calcium-binding domain), two Ig-like domains, and a novel C-terminal domain. Mahya may be involved in learning and memory and in processing of sensory information in Hymenoptera and vertebrates. Follistatin is a secreted, multidomain protein that binds activins with high affinity and antagonizes their signaling.

Pssm-ID: 409399 [Multi-domain] Cd Length: 93 Bit Score: 43.79 E-value: 4.22e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  600 RIYrmPEDQVARRGTTVQLECRVKHDPSLKLTvsWLKDDEPLyignrMKKEDDSLTIFG---------VAERDQGSYTCV 670
Cdd:cd05736      4 RVY--PEFQAKEPGVEASLRCHAEGIPLPRVQ--WLKNGMDI-----NPKLSKQLTLIAngselhisnVRYEDTGAYTCI 74

                           90
                   ....*....|..
gi 2217265341  671 ASTE--LDQDLA 680
Cdd:cd05736     75 AKNEggVDEDIS 86

Fifth Ig-like domain of Roundabout (Robo) homolog 1/2, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth Ig-like domain of Roundabout (Robo) homolog 1/2 and similar domains. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, -2, and -3), and three mammalian Slit homologs (Slit-1,-2, -3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, -2, and -3 are expressed by commissural neurons in the vertebrate spinal cord and Slits 1, -2, -3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of slit responsiveness, antagonizes slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. The fifth Ig-like domain of Robo 1 and 2 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors

Pssm-ID: 409544 [Multi-domain] Cd Length: 87 Bit Score: 43.25 E-value: 4.50e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  417 LDEPKNLILAPGEDGRLVCRANGNPKPTVQWMVNGEPLQSAPPNPNREVAGdTIIFRDTQISSRAVYQCNTSNEHGYLLA 496
Cdd:cd20952      3 LQGPQNQTVAVGGTVVLNCQATGEPVPTISWLKDGVPLLGKDERITTLENG-SLQIKGAEKSDTGEYTCVALNLSGEATW 81


                   ....*.
gi 2217265341  497 NAFVSV 502
Cdd:cd20952     82 SAVLDV 87

Second immunoglobulin (Ig)-like domain of the receptor protein tyrosine phosphatase (RPTP)-F; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in the receptor protein tyrosine phosphatase (RPTP)-F, also known as LAR. LAR belongs to the RPTP type IIa subfamily. Members of this subfamily are cell adhesion molecule-like proteins involved in central nervous system (CNS) development. They have large extracellular portions comprised of multiple Ig-like domains and two to nine fibronectin type III (FNIII) domains and a cytoplasmic portion having two tandem phosphatase domains.

Pssm-ID: 409400 [Multi-domain] Cd Length: 91 Bit Score: 43.46 E-value: 4.56e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  502 VLDVPPRMlsprnqliRVILYNRT-RLDCPFFGSPIPTLRWFKNGQGSNLDGGNYHV--YENGSLEIKMIRKEDQGIYTC 578
Cdd:cd05738      1 IIDMGPQL--------KVVEKARTaTMLCAASGNPDPEISWFKDFLPVDTATSNGRIkqLRSGALQIENSEESDQGKYEC 72


                   ....*..
gi 2217265341  579 VATNILG 585
Cdd:cd05738     73 VATNSAG 79

First immunoglobulin (Ig)-like constant domain in Robo (roundabout) receptors, and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain in Roundabout (Robo) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit1, Slit2, Slit3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit1, Slit2,and Slit3 are expressed at the ventral midline. Robo3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site.

Pssm-ID: 409490 [Multi-domain] Cd Length: 99 Bit Score: 43.31 E-value: 5.53e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  527 LDCPFFGSPIPTLRWFKNGQ---GSNLDGGNYH-VYENGSLEIKMI-----RKEDQGIYTCVATNILGKA 587
Cdd:cd07693     20 LNCKAEGRPTPTIQWLKNGQpleTDKDDPRSHRiVLPSGSLFFLRVvhgrkGRSDEGVYVCVAHNSLGEA 89

Immunoglobulin (Ig)-like domain of myotilin, palladin, and myopalladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain in myotilin, palladin, and myopalladin. Myotilin, palladin, and myopalladin function as scaffolds that regulate actin organization. Myotilin and myopalladin are most abundant in skeletal and cardiac muscle; palladin is ubiquitously expressed in the organs of developing vertebrates and plays a key role in cellular morphogenesis. The three family members each interact with specific molecular partners with all three binding to alpha-actinin; In addition, palladin also binds to vasodilator-stimulated phosphoprotein (VASP) and ezrin, myotilin binds to filamin and actin, and myopalladin also binds to nebulin and cardiac ankyrin repeat protein (CARP). This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409405 [Multi-domain] Cd Length: 91 Bit Score: 43.25 E-value: 5.53e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  603 RMPEDQVARRGTTVQLECRVKHDPSLKLTvsWLKDDEPLYIGNRMKKEDD-----SLTIFGVAERDQGSYTCVASTELDQ 677
Cdd:cd05744      5 QAPGDLEVQEGRLCRFDCKVSGLPTPDLF--WQLNGKPVRPDSAHKMLVRengrhSLIIEPVTKRDAGIYTCIARNRAGE 82


                   ....*....
gi 2217265341  678 DLAKAYLTV 686
Cdd:cd05744     83 NSFNAELVV 91

Fourth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409548 [Multi-domain] Cd Length: 96 Bit Score: 43.32 E-value: 5.61e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217265341  527 LDCPFFGSPIPTLRWFKNGQGSNLDG----GNYhVYENG----SLEIKMIRKEDQGIYTCVATNILGKAENQVRLEV 595
Cdd:cd20956     21 LKCVASGNPLPQITWTLDGFPIPESPrfrvGDY-VTSDGdvvsYVNISSVRVEDGGEYTCTATNDVGSVSHSARINV 96

Second C-terminal immunoglobulin (Ig)-like domain of palladin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of palladin. Palladin belongs to the palladin-myotilin-myopalladin family. Proteins belonging to this family contain multiple Ig-like domains and function as scaffolds, modulating actin cytoskeleton. Palladin binds to alpha-actinin ezrin, vasodilator-stimulated phosphoprotein VASP, SPIN90 (also known as DIP or mDia interacting protein), and Src. Palladin also binds F-actin directly, via its Ig3 domain. Palladin is expressed as several alternatively spliced isoforms, having various combinations of Ig-like domains, in a cell-type-specific manner. It has been suggested that palladin's different Ig-like domains may be specialized for distinct functions. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409582 Cd Length: 91 Bit Score: 43.17 E-value: 5.81e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  414 PYWLDEPKNLILAPGEDGRLVCRANGNPKPTVQWMVNGEPLQ--SAPPNPNREVAGDTIIFRDTQISSRAVYQCNTSNEH 491
Cdd:cd20990      1 PHFLQAPGDLTVQEGKLCRMDCKVSGLPTPDLSWQLDGKPIRpdSAHKMLVRENGVHSLIIEPVTSRDAGIYTCIATNRA 80


                   .
gi 2217265341  492 G 492
Cdd:cd20990     81 G 81

Immunoglobulin-like Ig0 domain of basigin-1 (BSG1) and similar proteins; The members here are composed of the immunoglobulin (Ig) domain of the collagenase stimulatory factor, basigin-1 (BSG1; also known as Cluster of Differentiation 147 (CD147) and Extracellular Matrix Metalloproteinase Inducer (EMMPRIN)) and similar proteins. CD147 is a transmembrane glycoprotein that belongs to the immunoglobulin superfamily. It is expressed in nearly all cells including platelets and fibroblasts and is involved in inflammatory diseases, and cancer progression. CD147 is highly expressed in several cancers and used as a prognostic marker. The two primary isoforms of CD147 that are related to cancer progression have been identified: CD147 Ig1-Ig2 (also called Basigin-2) that is ubiquitously expressed in most tissues and CD147 Ig0-Ig1-Ig2 (also called Basigin-1) that is retinal specific and implicated in retinoblastoma. Studies showed that CD147 Ig0 domain is a potent stimulator of interleukin-6 and suggest that the CD147 Ig0 dimer is the functional unit required for activity.

Pssm-ID: 409534 Cd Length: 116 Bit Score: 43.80 E-value: 6.38e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  511 SPRNQliRVILYNRTRLDCPFFGSPIPTLRWFKNGQGSN------LDG---------GNYHVYENGSLEIKMIRKEDQGI 575
Cdd:cd20940      6 SPLSQ--QRLVGDSVELHCEAVGSPIPEIQWWFEGQEPNeicsqlWDGarldrvhinATYHQHATSTISIDNLTEEDTGT 83


                   ....*..
gi 2217265341  576 YTCVATN 582
Cdd:cd20940     84 YECRASN 90

First immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409547 Cd Length: 99 Bit Score: 43.17 E-value: 6.38e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217265341  138 IECEAKGNPAPSFHWTRnSRFFNIAKDPRVSMRRRSGTLVI-DFRSGGRPEEYEGE-YQCFARNKFGTALSNRIRLQ 212
Cdd:cd20955     22 IECKASGNPMPEIIWIR-SDGTAVGDVPGLRQISSDGKLVFpPFRAEDYRQEVHAQvYACLARNQFGSIISRDVHVR 97

C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin, and similar domains; member of the I-set IgSF domains; The members here are composed of the C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin and similar proteins, including Caenorhabditis elegans and Aplysia californica Twitchin, Drosophila melanogaster Projectin, and similar proteins. These are very large muscle proteins containing multiple immunoglobulin (Ig)-like and fibronectin type III (FN3) domains and a single kinase domain near the C-terminus. In humans these proteins are called Titin. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig-like domain of the Twitchin is a member of the I-set IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins (titin, telokin, and twitchin), the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D.

Pssm-ID: 409541 [Multi-domain] Cd Length: 89 Bit Score: 43.09 E-value: 6.43e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  529 CPFFGSPIPTLRWFKNGQ---GSNLDGGNYHVYENGsLEIKMIRKEDQGIYTCVATNILGKAENQVRLEV 595
Cdd:cd20949     21 CEVKGEPQPNVTWHFNGQpisASVADMSKYRILADG-LLINKVTQDDTGEYTCRAYQVNSIASDMQERTV 89

Immunoglobulin domain of human Synaptic Adhesion-Like Molecule 5 (SALM5) and similar proteins; member of the I-set of IgSF domains; This group contains the immunoglobulin domain of human Synaptic Adhesion-Like Molecule 5 (SALM5) and similar proteins. The SALM (for synaptic adhesion-like molecules; also known as Lrfn for leucine-rich repeat and fibronectin type III domain containing) family of adhesion molecules consists of five known members: SALM1/Lrfn2, SALM2/Lrfn1, SALM3/Lrfn4, SALM4/Lrfn3, and SALM5/Lrfn5. SALMs share a similar domain structure, containing leucine-rich repeats (LRRs), an immunoglobulin (Ig) domain, and a fibronectin III (FNIII) domain, followed by a transmembrane domain and a C-terminal PDZ-binding motif. SALM5 is implicated in autism spectrum disorders (ASDs) and schizophrenia, induces presynaptic differentiation in contacting axons. SALM5 interacts with the Ig domains of LAR (Leukocyte common Antigen-Related) family receptor protein tyrosine phosphatases (LAR-RPTPs; LAR, PTPdelta, and PTPsigma). In addition, PTPdelta is implicated in ASDs, ADHD, bipolar disorder, and restless leg syndrome. Studies have shown that LAR-RPTPs are novel and splicing-dependent presynaptic ligands for SALM5, and that they mediate SALM5-dependent presynaptic differentiation. Furthermore, SALM5 maintains AMPA receptor (AMPAR)-mediated excitatory synaptic transmission through mechanisms involving the interaction of SALM5 with LAR-RPTPs. This group belongs to the I-set of immunoglobulin superfamily (IgSF) domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409421 [Multi-domain] Cd Length: 88 Bit Score: 42.85 E-value: 6.59e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217265341  335 VLRGMDLLLECIASGVPTPDIAWYKKGGDLPSDKAKFENF-NKALRITNVSEEDSGEYFCLASNKMGSIRHTISVRV 410
Cdd:cd05764     12 VLEGQRATLRCKARGDPEPAIHWISPEGKLISNSSRTLVYdNGTLDILITTVKDTGAFTCIASNPAGEATARVELHI 88

immunoglobulin-like domain of telokin and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin (Ig) domain in telokin, the C-terminal domain of myosin light chain kinase which is identical to telokin, and similar proteins. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the telokin Ig domain lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409565 [Multi-domain] Cd Length: 88 Bit Score: 42.95 E-value: 6.65e-05

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217265341  343 LECIASGVPTPDIAWYKKGGDL-PSDKAKF---ENFNKALRITNVSEEDSGEYFCLASNKMGSIRHTISVRV 410
Cdd:cd20973     17 FDCKVEGYPDPEVKWMKDDNPIvESRRFQIdqdEDGLCSLIISDVCGDDSGKYTCKAVNSLGEATCSAELTV 88

First immunoglobulin (Ig) domain of contactin; member of the I-set of (Ig) superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409356 [Multi-domain] Cd Length: 96 Bit Score: 43.00 E-value: 6.67e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  324 MYPQGTASSQMVLrgmdlllECIASGVPTPDIAWYKKGGDL---PSDKAKFENFNkaLRITNVSE-EDSGEYFCLASNKM 399
Cdd:cd04967     12 IFPEDSDEKKVAL-------NCRARANPVPSYRWLMNGTEIdleSDYRYSLVDGT--LVISNPSKaKDAGHYQCLATNTV 82


                   ....*.
gi 2217265341  400 GSIRHT 405
Cdd:cd04967     83 GSVLSR 88

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor_like-1(FGFRL1); member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 is comprised of a signal peptide, three extracellular Ig-like modules, a transmembrane segment, and a short intracellular domain. FGFRL1 is expressed preferentially in skeletal tissues. Similar to FGF receptors, the expressed protein interacts specifically with heparin and with FGF2. FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409442 Cd Length: 92 Bit Score: 42.92 E-value: 7.53e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  421 KNLILAP-GEDGRLVCRANGNPKPTVQWMVNGEPLQSAPPNPNREVAGdTIIFRDTQISSRAVYQCNTSNEHGYLLANAF 499
Cdd:cd05856     11 RRVIARPvGSSVRLKCVASGNPRPDITWLKDNKPLTPPEIGENKKKKW-TLSLKNLKPEDSGKYTCHVSNRAGEINATYK 89


                   ...
gi 2217265341  500 VSV 502
Cdd:cd05856     90 VDV 92

Second immunoglobulin (Ig)-like domain of the receptor protein tyrosine phosphatase (RPTP)-F; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in the receptor protein tyrosine phosphatase (RPTP)-F, also known as LAR. LAR belongs to the RPTP type IIa subfamily. Members of this subfamily are cell adhesion molecule-like proteins involved in central nervous system (CNS) development. They have large extracellular portions comprised of multiple Ig-like domains and two to nine fibronectin type III (FNIII) domains and a cytoplasmic portion having two tandem phosphatase domains.

Pssm-ID: 409400 [Multi-domain] Cd Length: 91 Bit Score: 43.08 E-value: 7.58e-05

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217265341  345 CIASGVPTPDIAWYKKGgdLPSDKAKFENFNKALR-----ITNVSEEDSGEYFCLASNKMGS 401
Cdd:cd05738     21 CAASGNPDPEISWFKDF--LPVDTATSNGRIKQLRsgalqIENSEESDQGKYECVATNSAGT 80

Immunoglobulin (Ig)-like domain of NrCAM (Ng (neuronglia) CAM-related cell adhesion molecule); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of NrCAM (Ng (neuronglia) CAM-related cell adhesion molecule). NrCAM belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region, and an intracellular domain. NrCAM is primarily expressed in the nervous system.

Pssm-ID: 409458 Cd Length: 95 Bit Score: 42.66 E-value: 8.94e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  420 PKNLILAPGEDGRLVCRANGNPKPTVQWMVNG-------EPLQSAPPNpnrevAGDTIIfrDTQISSRA-----VYQCNT 487
Cdd:cd05874      8 PKDYIVDPRENIVIQCEAKGKPPPSFSWTRNGthfdidkDPKVTMKPN-----TGTLVI--NIMNGEKAeayegVYQCTA 80

                           90
                   ....*....|...
gi 2217265341  488 SNEHGYLLANAFV 500
Cdd:cd05874     81 RNERGAAVSNNIV 93

Fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related); The members here are composed of the fourth immunoglobulin (Ig)-like domain of L1, Ng-CAM (Neuron-glia CAM cell adhesion molecule), and NrCAM (Ng-CAM-related). These proteins belong to the L1 subfamily of cell adhesion molecules (CAMs) and are comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. These molecules are primarily expressed in the nervous system. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth.

Pssm-ID: 409367 [Multi-domain] Cd Length: 89 Bit Score: 42.44 E-value: 9.97e-05

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  605 PEDQVARRGTTVQLECRVKHDPslKLTVSWLKDDEPLYI---GNRMKKEDDSLTIFGVAERDQGSYTCVASTELDQDLAK 681
Cdd:cd04978      6 PPSLVLSPGETGELICEAEGNP--QPTITWRLNGVPIEPapeDMRRTVDGRTLIFSNLQPNDTAVYQCNASNVHGYLLAN 83


                   ....*.
gi 2217265341  682 AYLTVL 687
Cdd:cd04978     84 AFLHVL 89

Second Ig domain of the neural cell adhesion molecule contactin-2, and similar domains; The members here are composed of the second Ig domain of the neural cell adhesion molecule contactin-2. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (also called TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. The first four Ig domains form the intermolecular binding fragment which arranges as a compact U-shaped module by contacts between Ig domains 1 and 4, and domains 2 and 3. It has been proposed that a linear zipper-like array forms, from contactin-2 molecules alternatively provided by the two apposed membranes.

Pssm-ID: 409392 Cd Length: 88 Bit Score: 42.55 E-value: 1.05e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217265341  225 DPVVVQEGAPLTLQCNPPPGLPSPVIFWMSSSMEP-ITQDKR--VSQGhNGDLYFSNVMLQDMqTDYSCNARFH 295
Cdd:cd05727      3 DEVKVKEGWGVVLFCDPPPHYPDLSYRWLLNEFPNfIPEDGRrfVSQT-NGNLYIAKVEASDR-GNYSCFVSSP 74

Immunoglobulin (Ig)-like domain of human carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) domains 2, 4, and 6, and similar domains; The members here are composed of the second, fourth, and sixth immunoglobulin (Ig)-like domains in human carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) protein subfamily. The CEA family is a group of anchored or secreted glycoproteins expressed by epithelial cells, leukocytes, endothelial cells, and placenta. The CEA family is divided into the CEACAM and pregnancy-specific glycoprotein (PSG) subfamilies. This group represents the CEACAM subfamily. CEACAM1 has many important cellular functions; it is a cell adhesion molecule and a signaling molecule that regulates the growth of tumor cells, an angiogenic factor, and a receptor for bacterial and viral pathogens, including mouse hepatitis virus (MHV). In mice, four isoforms of CEACAM1 generated by alternative splicing have either two [D1, D4] or four [D1-D4] Ig-like domains on the cell surface.

Pssm-ID: 409402 [Multi-domain] Cd Length: 89 Bit Score: 42.38 E-value: 1.10e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217265341  343 LECIASGvPTPDIAWYKKGGDLP-SDKAKFENFNKALRITNVSEEDSGEYFCLASNKMGSIR 403
Cdd:cd05740     20 LTCEPET-QNTSYLWWFNGQSLPvTPRLTLSNGNRTLTLLNVTREDAGAYQCEISNPVSANR 80

Sixth immunoglobulin (Ig) domain of contactin-4; The members here are composed of the sixth immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-4. Contactins are neural cell adhesion molecules, and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The different contactins show different expression patterns in the central nervous system. Highest expression of contactin-4 is in testes, thyroid, small intestine, uterus, and brain. Contactin-4 plays a role in the response of neuroblastoma cells to differentiating agents, such as retinoids. The contactin 4 gene is associated with cerebellar degeneration in spinocerebellar ataxia type 16.

Pssm-ID: 409439 Cd Length: 102 Bit Score: 42.69 E-value: 1.12e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  597 DPTRIYRMPEDQVARRGTTVQLECRVKHDPSLKLTVSWL---------KDDEPLyigNRMKKEDDS--LTIFGVAERDQG 665
Cdd:cd05853      1 DPTRVMVPPSSMDVTVGESIVLPCQVSHDHSLDIVFTWSfnghlidfqKDGDHF---ERVGGQDSAgdLMIRSIQLKHAG 77

                           90       100
                   ....*....|....*....|.
gi 2217265341  666 SYTCVASTELDQDLAKAYLTV 686
Cdd:cd05853     78 KYVCMVQTSVDKLSAAADLIV 98

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor, and similar domains; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three Ig-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans. This group also contains fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409393 [Multi-domain] Cd Length: 95 Bit Score: 42.59 E-value: 1.20e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  414 PYWLDEPK---NLILAP-GEDGRLVCRANGNPKPTVQWMVNGEPL---QSAPPNPNREvAGDTIIFRDTQISSRAVYQCN 486
Cdd:cd05729      1 PRFTDTEKmeeREHALPaANKVRLECGAGGNPMPNITWLKDGKEFkkeHRIGGTKVEE-KGWSLIIERAIPRDKGKYTCI 79


                   ....*.
gi 2217265341  487 TSNEHG 492
Cdd:cd05729     80 VENEYG 85

Seventh immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the seventh immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409546 [Multi-domain] Cd Length: 96 Bit Score: 42.30 E-value: 1.25e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  414 PYWLDEPKNLILAPGEDGRLVCRANGNPKPTVQWMvngeplQSAPPNPN--REVAGD---------TIIFRDTQISSRAV 482
Cdd:cd20954      2 PRWIVEPVDANVAAGQDVMLHCQADGFPTPTVTWK------KATGSTPGeyKDLLYDpnvrilpngTLVFGHVQKENEGH 75

                           90
                   ....*....|
gi 2217265341  483 YQCNTSNEHG 492
Cdd:cd20954     76 YLCEAKNGIG 85

Fourth immunoglobulin (Ig)-like domain of NrCAM (NgCAM-related cell adhesion molecule); The members here are composed of the fourth immunoglobulin (Ig)-like domain of NrCAM (NgCAM-related cell adhesion molecule). NrCAM belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six IG-like domains and five fibronectin type III domains, a transmembrane region, and an intracellular domain. NrCAM is primarily expressed in the nervous system.

Pssm-ID: 409454 Cd Length: 89 Bit Score: 42.28 E-value: 1.34e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217265341  129 IVDPRDNILIECEAKGNPAPSFHWTRNSRFFNIAkdPRVSMRRRSGTLVIdfrSGGRPEEYEGEYQCFARNKFGTALSN 207
Cdd:cd05868     10 VLSPGEDGTLICRANGNPKPSISWLTNGVPIEIA--PTDPSRKVDGDTII---FSKVQERSSAVYQCNASNEYGYLLAN 83

First immunoglobulin (Ig) domain of contactin-5; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-5. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains, anchored to the membrane by glycosylphosphatidylinositol. The different contactins show different expression patterns in the central nervous system. In rats, a lack of contactin-5 (NB-2) results in an impairment of the neuronal activity in the auditory system. Contactin-5 is expressed specifically in the postnatal nervous system, peaking at about 3 weeks postnatal. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala; lower levels of expression have been detected in the corpus callosum, caudate nucleus, and spinal cord. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409435 Cd Length: 96 Bit Score: 42.24 E-value: 1.37e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  527 LDCPFFGSPIPTLRWFKNGQGSNLDGGNYHVYENGSLEIKMIRK-EDQGIYTCVATNILG 585
Cdd:cd05848     24 LNCEARGNPVPTYRWLRNGTEIDTESDYRYSLIDGNLIISNPSEvKDSGRYQCLATNSIG 83

Second immunoglobulin (Ig)-like domain of protein tyrosine kinase (PTK) 7; The members here are composed of the second immunoglobulin (Ig)-like domain in protein tyrosine kinase (PTK) 7, also known as CCK4. PTK7 is a subfamily of the receptor protein tyrosine kinase family, and is referred to as an RPTK-like molecule. RPTKs transduce extracellular signals across the cell membrane and play important roles in regulating cell proliferation, migration, and differentiation. PTK7 is organized as an extracellular portion having seven Ig-like domains, a single transmembrane region, and a cytoplasmic tyrosine kinase-like domain. PTK7 is considered a pseudokinase as it has several unusual residues in some of the highly conserved tyrosine kinase (TK) motifs; it is predicted to lack TK activity. PTK7 may function as a cell-adhesion molecule. PTK7 mRNA is expressed at high levels in placenta, melanocytes, liver, lung, pancreas, and kidney. PTK7 is overexpressed in several cancers, including melanoma and colon cancer lines.

Pssm-ID: 409417 Cd Length: 95 Bit Score: 42.22 E-value: 1.40e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217265341  331 SSQMVLRgmdllleCIASGVPTPDIAWYKKGGDLPSDKAKFENFNKALRIT--NVSEEDSGEYFCLASNKMGSI 402
Cdd:cd05760     16 SSRVTLR-------CHIDGHPRPTYQWFRDGTPLSDGQGNYSVSSKERTLTlrSAGPDDSGLYYCCAHNAFGSV 82

First immunoglobulin (Ig)-like constant domain in Robo (roundabout) receptors, and similar domains; The members here are composed of the first immunoglobulin (Ig)-like domain in Roundabout (Robo) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit1, Slit2, Slit3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit1, Slit2,and Slit3 are expressed at the ventral midline. Robo3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be is the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site.

Pssm-ID: 409490 [Multi-domain] Cd Length: 99 Bit Score: 42.15 E-value: 1.44e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  331 SSQMVLRGMDLLLECIASGVPTPDIAWYKKGGDLPSDKAKFENFNKAL--------RITN--VSEEDSGEYFCLASNKMG 400
Cdd:cd07693      8 SDLIVSKGDPATLNCKAEGRPTPTIQWLKNGQPLETDKDDPRSHRIVLpsgslfflRVVHgrKGRSDEGVYVCVAHNSLG 87


                   ...
gi 2217265341  401 SIR 403
Cdd:cd07693     88 EAV 90

First immunoglobulin (Ig) domain of contactin-1; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409436 [Multi-domain] Cd Length: 95 Bit Score: 41.86 E-value: 1.67e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217265341  138 IECEAKGNPAPSFHWTRNSRFFNIAKDpRVSMrrRSGTLVIDfrsggRPEEYE--GEYQCFARNKFGTALSNRIRL 211
Cdd:cd05849     24 VNCRARANPFPIYKWRKNNLDIDLTND-RYSM--VGGNLVIN-----NPDKYKdaGRYVCIVSNIYGKVRSREATL 91

First immunoglobulin (Ig) domain of contactin-1; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409436 [Multi-domain] Cd Length: 95 Bit Score: 41.86 E-value: 1.70e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217265341  343 LECIASGVPTPDIAWYKKGGDLPSDKAKFENFNKALRITNVSE-EDSGEYFCLASNKMGSIRHT 405
Cdd:cd05849     24 VNCRARANPFPIYKWRKNNLDIDLTNDRYSMVGGNLVINNPDKyKDAGRYVCIVSNIYGKVRSR 87

C-terminal immunoglobulin (Ig)-like domain of M-protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of M-protein (also known as myomesin-2). M-protein is a structural protein localized to the M-band, a transverse structure in the center of the sarcomere, and is a candidate for M-band bridges. M-protein is modular consisting mainly of repetitive IG-like and fibronectin type III (FnIII) domains and has a muscle-type specific expression pattern. M-protein is present in fast fibers.

Pssm-ID: 143299 Cd Length: 92 Bit Score: 41.82 E-value: 1.75e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  335 VLRGMDLLLECIASGVPTPDIAWYKKGGDL-PSD-------KAKFenfnKALRITNVSEEDSGEYFCLASNKMGSIRHTI 406
Cdd:cd05891     13 IMEGKTLNLTCTVFGNPDPEVIWFKNDQDIeLSEhysvkleQGKY----ASLTIKGVTSEDSGKYSINVKNKYGGETVDV 88


                   ....
gi 2217265341  407 SVRV 410
Cdd:cd05891     89 TVSV 92

Third immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the third immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143222 [Multi-domain] Cd Length: 74 Bit Score: 41.46 E-value: 1.77e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217265341  529 CPFFGSPIPTLRWFKNGQGSNLDGgNYHVYENGSLEIKMIRKEDQGIYTCVATNILGKAENQVRLEV 595
Cdd:cd05745      9 CEAQGYPQPVIAWTKGGSQLSVDR-RHLVLSSGTLRISRVALHDQGQYECQAVNIVGSQRTVAQLTV 74

Immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM); The members here are composed of the immunoglobulin (Ig)-like domain of Down Syndrome Cell Adhesion molecule (DSCAM). DSCAM is a cell adhesion molecule expressed largely in the developing nervous system. The gene encoding DSCAM is located at human chromosome 21q22, the locus associated with the intellectual disability phenotype of Down Syndrome. DSCAM is predicted to be the largest member of the IG superfamily. It has been demonstrated that DSCAM can mediate cation-independent homophilic intercellular adhesion.

Pssm-ID: 409397 [Multi-domain] Cd Length: 97 Bit Score: 42.09 E-value: 1.88e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  506 PPR-MLSPRNQliRVILYNRTRLDCPFFGSPIPTLRW-FKNGQGSN------LDGGNYHVYENGSLEIKMIRKEDQGIYT 577
Cdd:cd05734      1 PPRfVVQPNDQ--DGIYGKAVVLNCSADGYPPPTIVWkHSKGSGVPqfqhivPLNGRIQLLSNGSLLIKHVLEEDSGYYL 78


                   ....*...
gi 2217265341  578 CVATNILG 585
Cdd:cd05734     79 CKVSNDVG 86

Immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 2 (VEGFR-2); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 2 (VEGFR-2). The VEGFRs have an extracellular component with seven Ig-like domains, a transmembrane segment, and an intracellular tyrosine kinase domain interrupted by a kinase-insert domain. VEGFRs bind VEGFs with high affinity at the Ig-like domains. VEGFR-2 (KDR/Flk-1) is a major mediator of the mitogenic, angiogenic and microvascular permeability-enhancing effects of VEGF-A; VEGF-A is important to the growth and maintenance of vascular endothelial cells and to the development of new blood- and lymphatic-vessels in physiological and pathological states. VEGF-A also interacts with VEGFR-1, which it binds more strongly than VEGFR-2. VEGFR-1 and VEGFR-2 may mediate a chemotactic and a survival signal in hematopoietic stem cells or leukemia cells. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409450 Cd Length: 89 Bit Score: 41.84 E-value: 1.92e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217265341  515 QLIRVILYNRTRLDCPFFGSPIPTLRWFKNGQGSNldgGNYHVYENGSLEIKMIRKEDQGIYTCVATNILGKAE 588
Cdd:cd05864     10 SLVEAKVGERVRIPVKYLGYPPPEIKWYKNGIPIE---SNHTIKAGHVLTIMEVTEKDAGNYTVVLTNPISKEK 80

Immunoglobulin variable domain (IgV); The members here are composed of the immunoglobulin variable domain (IgV). The IgV family contains the standard Ig superfamily V-set AGFCC'C"/DEB domain topology, and are components of immunoglobulin (Ig) and T cell receptors. The basic structure of Ig molecules is a tetramer of two light chains and two heavy chains linked by disulfide bonds. In Ig, each chain is composed of one variable domain (IgV) and one or more constant domains (IgC); these names reflect the fact that the variability in sequences is higher in the variable domain than in the constant domain. Within the variable domain, there are regions of even more variability called the hypervariable or complementarity-determining regions (CDRs) which are responsible for antigen binding. A predominant feature of most Ig domains is the disulfide bridge connecting 2 beta-sheets with a tryptophan residue packed against the disulfide bond. Ig superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Typically, the V-set domains have A, B, E and, D strands in one sheet and A', G, F, C, C', and C" strands in the other.

Pssm-ID: 409355 [Multi-domain] Cd Length: 111 Bit Score: 42.32 E-value: 1.99e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  331 SSQMVLRGMDLLLECIASG-VPTPDIAWYK----------------KGGDLPSDKAKFE-NFNKA----LRITNVSEEDS 388
Cdd:cd00099      6 RSLSVQEGESVTLSCEVSSsFSSTYIYWYRqkpgqgpefliylsssKGKTKGGVPGRFSgSRDGTssfsLTISNLQPEDS 85

                           90
                   ....*....|..
gi 2217265341  389 GEYFCLASNKMG 400
Cdd:cd00099     86 GTYYCAVSESGG 97

Fourth immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues, and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409388 Cd Length: 84 Bit Score: 41.41 E-value: 2.02e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  114 LTQPPTITKQSAKDhivdprdnILIECEAKGNPAPSFHWTRN------SRFFNIAKDPrvsmrrrsgtlviDFRSGGRPE 187
Cdd:cd05723      1 LKKPSNIYAHESMD--------IVFECEVTGKPTPTVKWVKNgdvvipSDYFKIVKEH-------------NLQVLGLVK 59

                           90
                   ....*....|....*....
gi 2217265341  188 EYEGEYQCFARNKFGTALS 206
Cdd:cd05723     60 SDEGFYQCIAENDVGNAQA 78

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409389 [Multi-domain] Cd Length: 87 Bit Score: 41.62 E-value: 2.06e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217265341  227 VVVQEGAPLTLQCNPPPGLPSPVIFWMSSSMEPITQDKRVSQGHNGDLYFSNVMLQDMQTdYSCNA 292
Cdd:cd05724      7 TQVAVGEMAVLECSPPRGHPEPTVSWRKDGQPLNLDNERVRIVDDGNLLIAEARKSDEGT-YKCVA 71

Third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule 1 (NCAM-1); member of the I-set of IgSF domains; The members here are composed of the third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule (NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-non-NCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions) through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain.

Pssm-ID: 143207 [Multi-domain] Cd Length: 95 Bit Score: 41.84 E-value: 2.10e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2217265341  428 GEDGRLVCRANGNPKPTVQWMVNGEPLQSAPPNPNREVAGDTIIFRDTQISSRAVYQCNTSNEHG 492
Cdd:cd05730     18 GQSVTLACDADGFPEPTMTWTKDGEPIESGEEKYSFNEDGSEMTILDVDKLDEAEYTCIAENKAG 82

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409389 [Multi-domain] Cd Length: 87 Bit Score: 41.23 E-value: 2.21e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  605 PEDQVARRGTTVQLEC---RVKHDPslklTVSWLKDDEPLYIGNRMKK--EDDSLTIFGVAERDQGSYTCVAS-TELDQD 678
Cdd:cd05724      4 PSDTQVAVGEMAVLECsppRGHPEP----TVSWRKDGQPLNLDNERVRivDDGNLLIAEARKSDEGTYKCVATnMVGERE 79


                   ....*...
gi 2217265341  679 LAKAYLTV 686
Cdd:cd05724     80 SRAARLSV 87

Fourth immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM); The members here are composed of the fourth immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region, and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM.

Pssm-ID: 409453 [Multi-domain] Cd Length: 89 Bit Score: 41.42 E-value: 2.38e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  126 KDHIVDPRDNILIECEAKGNPAPSFHWTRNS-RFFNIAKDPRvsMRRRSGTLVIdfrSGGRPEEyEGEYQCFARNKFGTA 204
Cdd:cd05867      7 QSHLYGPGETARLDCQVEGIPTPNITWSINGaPIEGTDPDPR--RHVSSGALIL---TDVQPSD-TAVYQCEARNRHGNL 80


                   ...
gi 2217265341  205 LSN 207
Cdd:cd05867     81 LAN 83

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM), and similar domains; The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM and human neurofascin.

Pssm-ID: 409394 [Multi-domain] Cd Length: 83 Bit Score: 41.24 E-value: 2.39e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217265341  608 QVARRGTTVQLECRVKHDPSLKltVSWLKDDEPLYiGNRMKKED--DSLTIFGVAERDQGSYTCVAS 672
Cdd:cd05731      5 TMVLRGGVLLLECIAEGLPTPD--IRWIKLGGELP-KGRTKFENfnKTLKIENVSEADSGEYQCTAS 68

Fifth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409550 [Multi-domain] Cd Length: 89 Bit Score: 41.40 E-value: 2.40e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  335 VLRGMDLLLECIASGVPTPDIAWYKKGGDLPSDKAK--FEnfNKALRITNV-SEEDSGEYFCLASNKMG-SIRHTISVRV 410
Cdd:cd20958     12 AVAGQTLRLHCPVAGYPISSITWEKDGRRLPLNHRQrvFP--NGTLVIENVqRSSDEGEYTCTARNQQGqSASRSVFVKV 89

Immunoglobulin V-set domain; This domain is found in antibodies as well as neural protein P0 and CTL4 amongst others.

Pssm-ID: 462230 Cd Length: 109 Bit Score: 42.06 E-value: 2.41e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  329 TASSQMVLRGMDLLLECIASG---VPTPDIAWYK---------------KGGDLPSDKAKFE------NFNKALRITNVS 384
Cdd:pfam07686    2 TPREVTVALGGSVTLPCTYSSsmsEASTSVYWYRqppgkgptfliayysNGSEEGVKKGRFSgrgdpsNGDGSLTIQNLT 81

                           90       100
                   ....*....|....*....|....*..
gi 2217265341  385 EEDSGEYFC-LASNKMGSIRHTISVRV 410
Cdd:pfam07686   82 LSDSGTYTCaVIPSGEGVFGKGTRLTV 108

Fifth immunoglobulin (Ig)-like domain of the carcinoembryonic antigen (CEA) related cell adhesion molecule 5 (CEACAM5) and similar domains; member of the C2-set IgSF domains; The members here are composed of the fifth immunoglobulin (Ig)-like domain of the carcinoembryonic antigen (CEA) related cell adhesion molecule 5 (CEACAM5) and similar domains. The CEA family is a group of anchored or secreted glycoproteins, expressed by epithelial cells, leukocytes, endothelial cells and placenta. The CEA family is divided into the CEACAM and pregnancy-specific glycoprotein (PSG) subfamilies. Carcinoembryonic antigen-related cell adhesion molecule 5 (CEACAM5), also known as CD66e (Cluster of Differentiation 66e), is a cell surface glycoprotein that plays a role in cell adhesion, intracellular signaling and tumor progression. Diseases associated with CEACAM5 include lung cancer and rectum cancer. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409540 Cd Length: 76 Bit Score: 40.94 E-value: 2.41e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217265341  336 LRGMDLLLECIASGVPTPDIAWYKKGgdlpsdkaKFENFNKALRITNVSEEDSGEYFCLASNKMGS 401
Cdd:cd20948      8 LSGENLNLSCHAASNPPAQYSWTING--------TFQTSSQELFLPAITENNEGTYTCSAHNSLTG 65

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409389 [Multi-domain] Cd Length: 87 Bit Score: 41.23 E-value: 2.44e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217265341  331 SSQMVLRGMDLLLECIAS-GVPTPDIAWYKKGGDLPSDKAKFENFNKA-LRITNVSEEDSGEYFCLASNKMG 400
Cdd:cd05724      5 SDTQVAVGEMAVLECSPPrGHPEPTVSWRKDGQPLNLDNERVRIVDDGnLLIAEARKSDEGTYKCVATNMVG 76

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409389 [Multi-domain] Cd Length: 87 Bit Score: 41.23 E-value: 2.46e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  419 EPKNLILAPGEDGRLVCRA-NGNPKPTVQWMVNGEPLQSAPPnPNREVAGDTIIFRDTQISSRAVYQCNTSNEHGYLLAN 497
Cdd:cd05724      3 EPSDTQVAVGEMAVLECSPpRGHPEPTVSWRKDGQPLNLDNE-RVRIVDDGNLLIAEARKSDEGTYKCVATNMVGERESR 81


                   ....*.
gi 2217265341  498 -AFVSV 502
Cdd:cd05724     82 aARLSV 87

Second immunoglobulin (Ig)-like domain of interleukin-1 receptor (IL1R), and similar domains; The members here are composed of the second immunoglobulin (Ig)-like domain of interleukin-1 receptor (IL1R). IL-1 alpha and IL-1 beta are cytokines which participate in the regulation of inflammation, immune responses, and hematopoiesis. These cytokines bind to the IL-1 receptor type 1 (IL1R1), which is activated on additional association with interleukin-1 receptor accessory protein (IL1RAP). IL-1 also binds a second receptor designated type II (IL1R2). Mature IL1R1 consists of three IG-like domains, a transmembrane domain, and a large cytoplasmic domain. Mature IL1R2 is organized similarly except that it has a short cytoplasmic domain. The latter does not initiate signal transduction. A naturally occurring cytokine IL-1RA (IL-1 receptor antagonist) is widely expressed and binds to IL-1 receptors, inhibiting the binding of IL-1 alpha and IL-1 beta. This group also contains ILIR-like 1 (IL1R1L) which maps to the same chromosomal location as IL1R1 and IL1R2.

Pssm-ID: 409586 Cd Length: 94 Bit Score: 41.30 E-value: 2.61e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217265341  353 PDIAWYKKGGDLPSDKAKFENFNKALRITNVSEEDSGEYFCLAS----NKMGSIRHTISVRVK 411
Cdd:cd20994     31 PKVQWYKDCKPLLLDDKRFAGLESDLLIFNVTVQDQGNYTCHTSytymGKQYNISRTISLIVL 93

Immunoglobulin I-set domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1); The members here are composed of the immunoglobulin I-set (IgI) domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1). Human Lingo-1 is a central nervous system-specific transmembrane glycoprotein also known as LERN-1, which functions as a negative regulator of neuronal survival, axonal regeneration, and oligodendrocyte differentiation and myelination. Lingo-1 is a key component of the Nogo receptor signaling complex (RTN4R/NGFR) in RhoA activation responsible for some inhibition of axonal regeneration by myelin-associated factors. The ligand-binding ectodomain of human Lingo-1 contains a bimodular, kinked structure composed of leucine-rich repeat (LRR) and immunoglobulin (Ig)-like modules. Diseases associated with Lingo-1 include mental retardation, autosomal recessive 64 and essential tremor. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the Lingo-1 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409561 Cd Length: 92 Bit Score: 41.22 E-value: 2.79e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  598 PTRIYRMPEDQV-ARRGTTVQLECRVKHDPSLklTVSWLKDDEPLYIGnrmkKEDDSLTIF--GVAE------RDQGSYT 668
Cdd:cd20969      1 RAAIRDRKAQQVfVDEGHTVQFVCRADGDPPP--AILWLSPRKHLVSA----KSNGRLTVFpdGTLEvryaqvQDNGTYL 74

                           90
                   ....*....|....*...
gi 2217265341  669 CVASTELDQDLAKAYLTV 686
Cdd:cd20969     75 CIAANAGGNDSMPAHLHV 92

First immunoglobulin (Ig) domain of contactin-2; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-2-like. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-2 (TAG-1, axonin-1) facilitates cell adhesion by homophilic binding between molecules in apposed membranes. It may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module by contacts between IG domains 1 and 4, and domains 2 and 3. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-2 is also expressed in retinal amacrine cells in the developing chick retina, corresponding to the period of formation and maturation of AC processes. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409437 [Multi-domain] Cd Length: 97 Bit Score: 41.45 E-value: 2.91e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  132 PRDNILIECEAKGNPAPSFHWTRNSRFFNIAKDPRvsMRRRSGTLVIDFRSGGRPeeyEGEYQCFARNKFGTALSNRIRL 211
Cdd:cd05850     19 AEEKVTLACRARASPPATYRWKMNGTELKMEPDSR--YRLVAGNLVISNPVKAKD---AGSYQCLASNRRGTVVSREASL 93


                   .
gi 2217265341  212 Q 212
Cdd:cd05850     94 R 94

Fifth domain (immunoglobulin-like) of Trk receptors TrkA, TrkB, and TrkC; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fifth domain of Trk receptors TrkA, TrkB, and TrkC, an immunoglobulin (Ig)-like domain which binds to neurotrophin. The Trk family of receptors are tyrosine kinase receptors. They are activated by dimerization, leading to autophosphorylation of intracellular tyrosine residues, and triggering the signal transduction pathway. TrkA, TrkB, and TrkC share significant sequence homology and domain organization. The first three domains are leucine-rich domains while the fourth and fifth domains are Ig-like domains playing a part in ligand binding. TrkA, TrkB, and TrkC mediate the trophic effects of the neurotrophin Nerve Growth Factor (NGF) family. TrkA is recognized by NGF. TrkB is recognized by brain-derived neurotrophic factor (BDNF) and neurotrophin (NT)-4. TrkC is recognized by NT-3. NT-3 is promiscuous as in some cell systems it activates TrkA and TrkB receptors. TrkA is a receptor found in all major NGF targets, including the sympathetic, trigeminal, and dorsal root ganglia, cholinergic neurons of the basal forebrain, and the striatum. TrKB transcripts are found throughout multiple structures of the central and peripheral nervous systems. The TrkC gene is expressed throughout the mammalian nervous system. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409360 Cd Length: 96 Bit Score: 41.24 E-value: 2.99e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217265341  533 GSPIPTLRWFKNGQGSN---------LDGGNYHVYENGSLEIKMIRKEDQGIYTCVATNILGKAENQV 591
Cdd:cd04971     24 GNPKPTLTWYHNGAVLNesdyirteiHYEAATPTEYHGCLKFDNPTHVNNGNYTLVASNEYGQDSKSI 91

Third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule 1 (NCAM-1); member of the I-set of IgSF domains; The members here are composed of the third immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule (NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-non-NCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions) through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain.

Pssm-ID: 143207 [Multi-domain] Cd Length: 95 Bit Score: 41.46 E-value: 3.02e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  610 ARRGTTVQLECRVKHDPslKLTVSWLKDDEPLYIG-NRMKKEDDS--LTIFGVAERDQGSYTCVASTELDQDLAKAYLTV 686
Cdd:cd05730     15 ANLGQSVTLACDADGFP--EPTMTWTKDGEPIESGeEKYSFNEDGseMTILDVDKLDEAEYTCIAENKAGEQEAEIHLKV 92


                   ..
gi 2217265341  687 LA 688
Cdd:cd05730     93 FA 94

Second immunoglobulin (Ig)-like domain of a Follistatin-related protein 5, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain found in human Follistatin-related protein 5 (FSTL5) and a follistatin-like molecule encoded by the CNS-related Mahya gene. Mahya genes have been retained in certain Bilaterian branches during evolution. They are conserved in Hymenoptera and Deuterostomes, but are absent from other metazoan species such as fruit fly and nematode. Mahya proteins are secretory, with a follistatin-like domain (Kazal-type serine/threonine protease inhibitor domain and EF-hand calcium-binding domain), two Ig-like domains, and a novel C-terminal domain. Mahya may be involved in learning and memory and in processing of sensory information in Hymenoptera and vertebrates. Follistatin is a secreted, multidomain protein that binds activins with high affinity and antagonizes their signaling.

Pssm-ID: 409399 [Multi-domain] Cd Length: 93 Bit Score: 41.09 E-value: 3.25e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217265341  427 PGEDGRLVCRANGNPKPTVQWMVNGEPLQSAPPNPNREVA-GDTIIFRDTQISSRAVYQCNTSNEHG 492
Cdd:cd05736     14 PGVEASLRCHAEGIPLPRVQWLKNGMDINPKLSKQLTLIAnGSELHISNVRYEDTGAYTCIAKNEGG 80

Eighth immunoglobulin (Ig)-like domain of human myosin light-chain kinase (MLCK) and similar protein; member of the I-set of IgSF domains; The members here are composed of the eighth immunoglobulin (Ig)-like domain of human myosin light-chain kinase (MLCK) and similar proteins. Myosin light-chain kinase (MLCK) is a key regulator of different forms of cell motility involving actin and myosin II. Agonist stimulation of smooth muscle cells increases cytosolic Ca2+ which binds calmodulin. This Ca2+-calmodulin complex in turn binds to and activates MLCK. Activated MLCK leads to the phosphorylation of the 20 kDa myosin regulatory light chain (RLC) of myosin II and the stimulation of actin-activated myosin MgATPase activity. MLCK is widely present in vertebrate tissues; it phosphorylates the 20 kDa RLC of both smooth and nonmuscle myosin II. Phosphorylation leads to the activation of the myosin motor domain and altered structural properties of myosin II. In smooth muscle MLCK it is involved in initiating contraction. In nonmuscle cells, MLCK may participate in cell division and cell motility; it has been suggested MLCK plays a role in cardiomyocyte differentiation and contraction through regulation of nonmuscle myosin II.

Pssm-ID: 409419 Cd Length: 99 Bit Score: 41.48 E-value: 3.27e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  598 PTRIYRMPEDQVARRGTTVQLECRVKHdpSLKLTVSWLKDDEPLYIGNRMKKED----DSLTIFGVAERDQGSYTCVAST 673
Cdd:cd05762      1 PPQIIQFPEDMKVRAGESVELFCKVTG--TQPITCTWMKFRKQIQEGEGIKIENtensSKLTITEGQQEHCGCYTLEVEN 78

                           90       100
                   ....*....|....*....|
gi 2217265341  674 ELDQDLAKAYLTVLaDQATP 693
Cdd:cd05762     79 KLGSRQAQVNLTVV-DKPDP 97

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM); The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains, five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM.

Pssm-ID: 409460 [Multi-domain] Cd Length: 83 Bit Score: 40.66 E-value: 3.38e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217265341  136 ILIECEAKGNPAPSFHWTRNSrffniakDP----RVSMRRRSGTLVIDfrsgGRPEEYEGEYQCFARNKFGTA 204
Cdd:cd05876     13 LVLECIAEGLPTPTVKWLRPS-------GPlppdRVKYQNHNKTLQLL----NVGESDDGEYVCLAENSLGSA 74

Immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor (VEGFR); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor (VEGFR). The VEGFRs have an extracellular component with seven Ig-like domains, a transmembrane segment, and an intracellular tyrosine kinase domain interrupted by a kinase-insert domain. The VEGFR family consists of three members, VEGFR-1 (Flt-1), VEGFR-2 (KDR/Flk-1), and VEGFR-3 (Flt-4). VEGFRs bind VEGFs with high affinity at the Ig-like domains. VEGF-A is important to the growth and maintenance of vascular endothelial cells and to the development of new blood- and lymphatic-vessels in physiological and pathological states. VEGFR-2 is a major mediator of the mitogenic, angiogenic, and microvascular permeability-enhancing effects of VEGF-A. VEGFR-1 may play an inhibitory part in these processes by binding VEGF and interfering with its interaction with VEGFR-2. VEGFR-1 has a signaling role in mediating monocyte chemotaxis. VEGFR-1 and VEGFR-2 may mediate a chemotactic and a survival signal in hematopoietic stem cells or leukemia cells. VEGFR-3 has been shown to be involved in tumor angiogenesis and growth. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409365 Cd Length: 90 Bit Score: 41.05 E-value: 3.72e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  349 GVPTPDIAWYKKGgdLPSDKAKFENFNKALRITNVSEEDSGEYFCLASNKMGSIRHTISV 408
Cdd:cd04976     29 AYPPPEVVWYKDG--LPLTEKARYLTRHSLIIKEVTEEDTGNYTILLSNKQSNVFKNLTA 86

Fourth Ig-like domain from smooth muscle myosin light chain kinase and similar domains ; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain from smooth muscle myosin light chain kinase (MYLK) and similar domains. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of this group shows that the fourth Ig-like domain from myosin light chain kinase lacks this strand and thus belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409568 [Multi-domain] Cd Length: 90 Bit Score: 40.70 E-value: 3.74e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  598 PTRIYRMPEDQVARRGTTVQLECRVKHDPSLKLTvsWLKDDEPL-YIGNRMKKEDDS--LTIFGVAERDQGSYTCVASTE 674
Cdd:cd20976      1 APSFSSVPKDLEAVEGQDFVAQCSARGKPVPRIT--WIRNAQPLqYAADRSTCEAGVgeLHIQDVLPEDHGTYTCLAKNA 78

                           90
                   ....*....|..
gi 2217265341  675 LDQDLAKAYLTV 686
Cdd:cd20976     79 AGQVSCSAWVTV 90

Immunoglobulin-like Ig0 domain of basigin-1 (BSG1) and similar proteins; The members here are composed of the immunoglobulin (Ig) domain of the collagenase stimulatory factor, basigin-1 (BSG1; also known as Cluster of Differentiation 147 (CD147) and Extracellular Matrix Metalloproteinase Inducer (EMMPRIN)) and similar proteins. CD147 is a transmembrane glycoprotein that belongs to the immunoglobulin superfamily. It is expressed in nearly all cells including platelets and fibroblasts and is involved in inflammatory diseases, and cancer progression. CD147 is highly expressed in several cancers and used as a prognostic marker. The two primary isoforms of CD147 that are related to cancer progression have been identified: CD147 Ig1-Ig2 (also called Basigin-2) that is ubiquitously expressed in most tissues and CD147 Ig0-Ig1-Ig2 (also called Basigin-1) that is retinal specific and implicated in retinoblastoma. Studies showed that CD147 Ig0 domain is a potent stimulator of interleukin-6 and suggest that the CD147 Ig0 dimer is the functional unit required for activity.

Pssm-ID: 409534 Cd Length: 116 Bit Score: 41.49 E-value: 3.75e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  332 SQMVLRGMDLLLECIASGVPTPDIAWYKKGGDlPS-------DKAKFENFN----------KALRITNVSEEDSGEYFCL 394
Cdd:cd20940      9 SQQRLVGDSVELHCEAVGSPIPEIQWWFEGQE-PNeicsqlwDGARLDRVHinatyhqhatSTISIDNLTEEDTGTYECR 87

                           90       100       110
                   ....*....|....*....|....*....|.
gi 2217265341  395 ASNKMGSIRHTISVRVKaapyWLDEPKNLIL 425
Cdd:cd20940     88 ASNDPDRNHLTRAPKVK----WIRSQANVLV 114

Second Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409564 [Multi-domain] Cd Length: 91 Bit Score: 41.03 E-value: 3.82e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  413 APYWLDEPKNLILAPGEDGRLVCRANGNPKPTVQWMVNGEPLQSAPpnpnrevagdtiifrDTQISsravyqcNTSNEHG 492
Cdd:cd20972      1 PPQFIQKLRSQEVAEGSKVRLECRVTGNPTPVVRWFCEGKELQNSP---------------DIQIH-------QEGDLHS 58


                   ....*..
gi 2217265341  493 YLLANAF 499
Cdd:cd20972     59 LIIAEAF 65

Fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; Members here are composed the fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1, Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409391 [Multi-domain] Cd Length: 98 Bit Score: 41.09 E-value: 3.83e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  512 PRNQLirVILYNRTRLDCPFFGSPIPTLRWFKNGQGSNL-------DGGNYHVYENGSLEIKMIRKEDQGIYTCVATNIL 584
Cdd:cd05726      6 PRDQV--VALGRTVTFQCETKGNPQPAIFWQKEGSQNLLfpyqppqPSSRFSVSPTGDLTITNVQRSDVGYYICQALNVA 83

                           90
                   ....*....|...
gi 2217265341  585 GKAENQVRLEVKD 597
Cdd:cd05726     84 GSILAKAQLEVTD 96

First immunoglobulin (Ig) domain of contactin; member of the I-set of (Ig) superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of contactins. Contactins are neural cell adhesion molecules and are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. The first four Ig domains form the intermolecular binding fragment, which arranges as a compact U-shaped module via contacts between Ig domains 1 and 4, and between Ig domains 2 and 3. Contactin-2 (TAG-1, axonin-1) may play a part in the neuronal processes of neurite outgrowth, axon guidance and fasciculation, and neuronal migration. This group also includes contactin-1 and contactin-5. The different contactins show different expression patterns in the central nervous system. During development and in adulthood, contactin-2 is transiently expressed in subsets of central and peripheral neurons. Contactin-5 is expressed specifically in the rat postnatal nervous system, peaking at about 3 weeks postnatal, and a lack of contactin-5 (NB-2) results in an impairment of neuronal activity in the rat auditory system. Contactin-5 is highly expressed in the adult human brain in the occipital lobe and in the amygdala. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409356 [Multi-domain] Cd Length: 96 Bit Score: 41.07 E-value: 3.86e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  527 LDCPFFGSPIPTLRWFKNGQGSNLDGGNYHVYENGSLEIKM-IRKEDQGIYTCVATNILG 585
Cdd:cd04967     24 LNCRARANPVPSYRWLMNGTEIDLESDYRYSLVDGTLVISNpSKAKDAGHYQCLATNTVG 83

Immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 3 (VEGFR-3); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 3 (VEGFR-3). The VEGFRs have an extracellular component with seven Ig-like domains, a transmembrane segment, and an intracellular tyrosine kinase domain interrupted by a kinase-insert domain. VEGFRs bind VEGFs with high affinity at the Ig-like domains. VEGFR-3 (Flt-4) binds two members of the VEGF family (VEGF-C and VEGF-D) and is involved in tumor angiogenesis and growth. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409449 Cd Length: 88 Bit Score: 40.69 E-value: 4.02e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  348 SGVPTPDIAWYKKGGDLPSdkakfENFNKALRITNVSEEDSGEYFCLASNKMGSIRHTIS 407
Cdd:cd05863     29 AAYPPPEFQWYKDGKLISG-----KHSPHSLQIKDVTEASAGTYTLVLWNSAAGLEKRIS 83

agrin-responsive second immunoglobulin-like domains (Ig2) of the Muscle-specific kinase (MuSK) ectodomain; a member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin-like (Ig) domains of the Muscle-specific kinase (MuSK) ectodomain. MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409560 [Multi-domain] Cd Length: 88 Bit Score: 40.69 E-value: 4.31e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  113 ELTQPPTITKQSAKDHIVDPrdnilieCEAKGNPAPSFHWTRNSRFfnIAKDPRVSMRRrSGTLVIDfrsgGRPEEYEGE 192
Cdd:cd20968      1 KITRPPTNVTIIEGLKAVLP-------CTTMGNPKPSVSWIKGDDL--IKENNRIAVLE-SGSLRIH----NVQKEDAGQ 66

                           90       100
                   ....*....|....*....|.
gi 2217265341  193 YQCFARNKFGTALSNRIRLQV 213
Cdd:cd20968     67 YRCVAKNSLGIAYSKPVTIEV 87

C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin, and similar domains; member of the I-set IgSF domains; The members here are composed of the C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin and similar proteins, including Caenorhabditis elegans and Aplysia californica Twitchin, Drosophila melanogaster Projectin, and similar proteins. These are very large muscle proteins containing multiple immunoglobulin (Ig)-like and fibronectin type III (FN3) domains and a single kinase domain near the C-terminus. In humans these proteins are called Titin. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig-like domain of the Twitchin is a member of the I-set IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins (titin, telokin, and twitchin), the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D.

Pssm-ID: 409541 [Multi-domain] Cd Length: 89 Bit Score: 40.39 E-value: 4.86e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217265341  330 ASSQMVLRGMDLLLECIASGVPTPDIAWYKKGGDLPSDKA---KFENFNKALRITNVSEEDSGEYFCLASNKMG 400
Cdd:cd20949      6 AYVTTVKEGQSATILCEVKGEPQPNVTWHFNGQPISASVAdmsKYRILADGLLINKVTQDDTGEYTCRAYQVNS 79

Immunoglobulin (Ig)-like ectodomain of the LRIG1 (Leucine-rich Repeats And Immunoglobulin-like Domains Protein 1) and similar proteins; member of the I-set of IgSF domains; The members here are composed of subgroup of the immunoglobulin (Ig) domain found in the Ig superfamily. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond. The ectodomain of LRIG1 has two distinct regions: the proposed 15 LRRs and three Ig-like domains closer to the membrane. LRIG1 has been reported to interact with many receptor tyrosine kinases, GDNF/c-Ret, E-cadherin, JAK/STAT, c-Met, and the EGFR family signaling systems. Immunoglobulin Superfamily (IgSF) domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The structure of the LRIG1 extracellular Ig domain lacks a C" strand and thus is better described as a member of the I-set of IgSF domains.

Pssm-ID: 409420 [Multi-domain] Cd Length: 91 Bit Score: 40.68 E-value: 5.14e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217265341  512 PRNqlIRVILYNRTRLDCPFFGSPIPTLRWFKNGqGSNLDGG---NYHVY-ENGSLEIKMIRKEDQGIYTCVATNILG 585
Cdd:cd05763      6 PHD--ITIRAGSTARLECAATGHPTPQIAWQKDG-GTDFPAArerRMHVMpEDDVFFIVDVKIEDTGVYSCTAQNSAG 80

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM), and similar domains; The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, and spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM and human neurofascin.

Pssm-ID: 409394 [Multi-domain] Cd Length: 83 Bit Score: 40.09 E-value: 5.45e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  133 RDNIL-IECEAKGNPAPSFHWTR------NSRFF--NIAKdprvsmrrrsgTLVIDFRSggrpEEYEGEYQCFARNKFGT 203
Cdd:cd05731      9 RGGVLlLECIAEGLPTPDIRWIKlggelpKGRTKfeNFNK-----------TLKIENVS----EADSGEYQCTASNTMGS 73


                   .
gi 2217265341  204 A 204
Cdd:cd05731     74 A 74

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor, and similar domains; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three Ig-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans. This group also contains fibroblast growth factor (FGF) receptor like-1(FGFRL1). FGFRL1 does not have a protein tyrosine kinase domain at its C-terminus; neither does its cytoplasmic domain appear to interact with a signaling partner. It has been suggested that FGFRL1 may not have any direct signaling function, but instead acts as a decoy receptor trapping FGFs and preventing them from binding other receptors.

Pssm-ID: 409393 [Multi-domain] Cd Length: 95 Bit Score: 40.28 E-value: 6.30e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217265341  613 GTTVQLECRVKHDPslKLTVSWLKDDEPLYI-----GNRMKKEDDSLTIFGVAERDQGSYTCVASTE 674
Cdd:cd05729     19 ANKVRLECGAGGNP--MPNITWLKDGKEFKKehrigGTKVEEKGWSLIIERAIPRDKGKYTCIVENE 83

Sixth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the sixth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409551 Cd Length: 94 Bit Score: 40.17 E-value: 6.59e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217265341  338 GMDLLLECIASGVPTP-DIAWYKKGGDLPSDKA----KFENFNKALRITNVSEEDSGEYFCLASNKMGSIRHTISVRV 410
Cdd:cd20959     17 GMRAQLHCGVPGGDLPlNIRWTLDGQPISDDLGitvsRLGRRSSILSIDSLEASHAGNYTCHARNSAGSASYTAPLTV 94

Fourth immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the fourth immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted, and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143223 Cd Length: 69 Bit Score: 39.47 E-value: 6.82e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  343 LECIASGVPTPDIAWYKKGGDLpSDKAKFE-NFNKALRITNVSEEDSGEYFCLASNKMGS 401
Cdd:cd05746      3 IPCSAQGDPEPTITWNKDGVQV-TESGKFHiSPEGYLAIRDVGVADQGRYECVARNTIGY 61

Third immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C, and C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409549 [Multi-domain] Cd Length: 88 Bit Score: 39.82 E-value: 7.30e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217265341  420 PKNLILAPGEDGRLVCRANGNPKPTVQWMVNGEPLqsapPNPNR--EVAGDTIIFRDTQISSRAVYQCNTSNE 490
Cdd:cd20957      8 PPVQTVDFGRTAVFNCSVTGNPIHTVLWMKDGKPL----GHSSRvqILSEDVLVIPSVKREDKGMYQCFVRND 76

Immunoglobulin (Ig)-like domain of the human basement membrane heparan sulfate proteoglycan perlecan and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain of the human basement membrane heparan sulfate proteoglycan perlecan, also known as HSPG2, and similar proteins. Perlecan consists of five domains: domain I has three putative heparan sulfate attachment sites, domain II has four LDL receptor-like repeats, and one Ig-like repeat, domain III resembles the short arm of laminin chains, domain IV has multiple Ig-like repeats (21 repeats in human perlecan), and domain V resembles the globular G domain of the laminin A chain and internal repeats of EGF. Perlecan may participate in a variety of biological functions including cell binding, LDL-metabolism, basement membrane assembly and selective permeability, calcium binding, and growth- and neurite-promoting activities.

Pssm-ID: 143220 Cd Length: 78 Bit Score: 39.78 E-value: 7.80e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2217265341  428 GEDGRLVCRANGNPKPTVQWMVNGEPLQSAPPNPNREVAG-DTIIFRDTQISSRAVYQCNTSNEHGYLLAN 497
Cdd:cd05743      1 GETVEFTCVATGVPTPIINWRLNWGHVPDSARVSITSEGGyGTLTIRDVKESDQGAYTCEAINTRGMVFGI 71

Third immunoglobulin domain in Cluster of Differentiation (CD) 22; member of the Constant 2 (C2)-set of IgSF domains; The members here are composed of the third immunoglobulin domain in Cluster of Differentiation (CD) 22 (also known as Siglec-2). CD22, a sialic-acid binding immunoglobulin type-lectin (Siglec) family member, is an inhibitory co-receptor of the B-cell receptor (BCR). The inhibitory function of CD22 and its restricted expression on B cells makes CD22 an attractive target against dysregulated B cells that cause autoimmune diseases and B-cell-derived cancers. CD22 plays a vital role in establishing a baseline level of B-cell inhibition, and thus is an important determinant of homeostasis in humoral immunity. Siglecs are primarily expressed on immune cells and recognize sialic acid-containing glycan ligands. Siglecs are organized as an extracellular module composed of Ig-like domains (an N-terminal variable set of Ig-like carbohydrate recognition domains, and 1 to 16 constant Ig-like domains), followed by transmembrane and short cytoplasmic domains. Human Siglecs are classified into two subgroups, one subgroup is comprised of sialoadhesin (Siglec-1), CD22 (Siglec-2), and MAG (Siglec-4, myelin-associated glycoprotein), the other subgroup is comprised of CD33-related Siglecs which include CD33 (Siglec-3) and human Siglecs 5-11. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. This group belongs to the C2-set of IgSF domains, having A, B, and E strands in one beta-sheet and A', G, F, C' in the other. Unlike other Ig domain sets, the C2-set lacks the D strand.

Pssm-ID: 409531 Cd Length: 88 Bit Score: 39.78 E-value: 8.09e-04

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217265341  605 PEDQVARRGTTVQLECRVKHDPSLKLTVSWLKDdeplyiGNRMKKEDD-SLTIFGVAERDQGSYTCVASTEL 675
Cdd:cd20937      9 PSDAIVREGDSVTMTCEVSSSNPEYTTVSWLKD------GTSLKKQNTfTLNLREVTKDQSGKYCCQVSNDV 74

Immunoglobulin (Ig)-like domain of carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain in carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) and related domains. The CEA family is a group of anchored or secreted glycoproteins, expressed by epithelial cells, leukocytes, endothelial cells and placenta. The CEA family is divided into the CEACAM and pregnancy-specific glycoprotein (PSG) subfamilies. This group represents the CEACAM subfamily. CEACAM1 has many important cellular functions: it is a cell adhesion molecule and a signaling molecule that regulates the growth of tumor cells, an angiogenic factor, and a receptor for bacterial and viral pathogens, including mouse hepatitis virus (MHV). In mice, four isoforms of CEACAM1 generated by alternative splicing have either two (D1, D4) or four (D1-D4) Ig-like domains on the cell surface. This family corresponds to the D1 Ig-like domain. Also belonging to this group is the N-terminal immunoglobulin (Ig)-like domain of the signaling lymphocyte activation molecule (SLAM) family, CD84-like family. The SLAM family is a group of immune-cell specific receptors that can regulate both adaptive and innate immune responses. SLAM family proteins are organized as an extracellular domain with having two or four Ig-like domains, a single transmembrane segment, and a cytoplasmic region having Tyr-based motifs. The extracellular domain is organized as a membrane-distal Ig variable (IgV) domain that is responsible for ligand recognition and a membrane-proximal truncated Ig constant-2 (IgC2) domain.

Pssm-ID: 409403 Cd Length: 102 Bit Score: 40.19 E-value: 8.75e-04

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2217265341  539 LRWFKNGQG---SNLDGGNYHVYENGSLEIKMIRKEDQGIYTCVATNILGKAEN-QVRLEV 595
Cdd:cd05741     42 AEYENSSDEfraGSAFSGREYIYTNGSLLIQNITLSDTGFYTLESTNIGGKTESaTFQLHV 102

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 39.49 E-value: 9.38e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  512 PRNQLIRVILYNRTRLDC-PFFGSPIPTLRWFKNGQGSNLdgGNYHVYENG-----SLEIKMIRKEDQGIYTCVATNILG 585
Cdd:pfam00047    1 SAPPTVTVLEGDSATLTCsASTGSPGPDVTWSKEGGTLIE--SLKVKHDNGrttqsSLLISNVTKEDAGTYTCVVNNPGG 78


                   ..
gi 2217265341  586 KA 587
Cdd:pfam00047   79 SA 80

Second Ig-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of the giant muscle protein titin Z1z2 in the sarcomeric Z-disk and similar proteins. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the titin Z1z2 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409564 [Multi-domain] Cd Length: 91 Bit Score: 39.87 E-value: 9.48e-04

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  598 PTRIYRMPEDQVARRGTTVQLECRVKHDPSLKltVSWLKDDEPLY--IGNRMKKEDD--SLTIFGVAERDQGSYTCVAST 673
Cdd:cd20972      1 PPQFIQKLRSQEVAEGSKVRLECRVTGNPTPV--VRWFCEGKELQnsPDIQIHQEGDlhSLIIAEAFEEDTGRYSCLATN 78

                           90
                   ....*....|...
gi 2217265341  674 ELDQDLAKAYLTV 686
Cdd:cd20972     79 SVGSDTTSAEIFV 91

Immunoglobulin (Ig) constant domain of the complement receptor of the immunoglobulin superfamily (CRIg); The members here are composed of the Immunoglobulin (Ig) constant domain of the complement receptor of the immunoglobulin superfamily (CRIg). The N-terminal domain of CRIg (also referred to as Z39Ig and V-set and Ig domain-containing 4 (VSIG4)) belongs to the IgV family of immunoglobulin-like domains while the C-terminal domain of CRIg belongs to the IgC family of immunoglobulin-like domains. CRIg plays a role in the complement system, an inhibitor of the alternative pathway convertases, and a negative regulator of T cell activation. The Ig superfamily is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. Members of this group are components of immunoglobulin, neuroglia, cell surface glycoproteins such as T-cell receptors, CD2, CD4, CD8, and membrane glycoproteins such as butyrophilin and chondroitin sulfate proteoglycan core protein. A predominant feature of most Ig domains is a disulfide bridge connecting the two beta-sheets with a tryptophan residue packed against the disulfide bond.

Pssm-ID: 409504 Cd Length: 86 Bit Score: 39.35 E-value: 1.17e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217265341  335 VLRGMDLLLECIASGVPTPDIAWYKK--GGDLPSDKAKFEN--FNKALritnVSeeDSGEYFCLASNKMGSIRHTISVR 409
Cdd:cd16082     10 VPQGMRISLQCQAWGSPPISYVWYKEqtNNQEPIKVAALSTllFKPAV----VA--DSGSYFCTAKGRVGSEQRSDIVK 82

Fourth immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the fourth immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues, and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409388 Cd Length: 84 Bit Score: 39.10 E-value: 1.17e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  605 PEDQVARRGTTVQLECRVKHDPSLklTVSWLKDDEPLYIGNRMK-KEDDSLTIFGVAERDQGSYTCVASTELDQDLAKAY 683
Cdd:cd05723      4 PSNIYAHESMDIVFECEVTGKPTP--TVKWVKNGDVVIPSDYFKiVKEHNLQVLGLVKSDEGFYQCIAENDVGNAQASAQ 81


                   ...
gi 2217265341  684 LTV 686
Cdd:cd05723     82 LII 84

Immunoglobulin (Ig)-like domain of semaphorin 4D (Sema4D) and similar proteins; The members here are composed of the immunoglobulin (Ig)-like domain of semaphorin 4D (Sema4D) and similar proteins. Sema4D is a Class IV semaphorin. Semaphorins are classified based on structural features additional to the Sema domain. Sema4D has extracellular Sema and Ig domains, a transmembrane domain, and a short cytoplasmic domain. Sema4D plays a part in the development of GABAergic synapses. Sema4D in addition is an immune semaphorin. It is abundant on resting T cells; its expression is weak on resting B cells and antigen presenting cells (APCs), but is upregulated by various stimuli. The receptor used by Sema4D in the immune system is CD72. Sem4D enhances the activation of B cells and DCs through binding CD72, perhaps by reducing CD72s inhibitory signals. The receptor used by Sema4D in the non-lymphatic tissues is plexin-B1. Sem4D is anchored to the cell surface but its extracellular domain can be released from the cell surface by a metalloprotease-dependent process. Sem4D may mediate its effects in its membrane-bound form and/or its cleaved form.

Pssm-ID: 409457 Cd Length: 87 Bit Score: 39.41 E-value: 1.19e-03

                           10        20        30        40        50
                   ....*....|....*....|....*....|....*....|....*....|..
gi 2217265341  357 WYKKGGDLPSDKAKFENFNKALRITNVSEEDSGEYFCLASNKMGSIRHTISV 408
Cdd:cd05873     29 WKFQGKVLKAESPKYGLYGDGLLIFNASEADAGRYQCLSVEKSKAKTFFQTV 80

Third immunoglobulin (Ig)-like domain of the receptor protein tyrosine phosphatase (RPTP)-F (also known as LAR), type IIa; member of the I-set of IgSF domains; The members here are composed of the third immunoglobulin (Ig)-like domain found in the receptor protein tyrosine phosphatase (RPTP)-F, also known as LAR. LAR belongs to the RPTP type IIa subfamily. Members of this subfamily are cell adhesion molecule-like proteins involved in central nervous system (CNS) development. They have large extracellular portions comprised of multiple Ig-like domains and two to nine fibronectin type III (FNIII) domains and a cytoplasmic portion having two tandem phosphatase domains. Included in this group is Drosophila LAR (DLAR).

Pssm-ID: 409401 Cd Length: 82 Bit Score: 39.11 E-value: 1.22e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  512 PRNQliRVILYNRTRLDCPFFGSPIPTLRWFKNGQgsNLDGGNYHVYENGSLEIKMIRkeDQGIYTCVATNILGKAENQV 591
Cdd:cd05739      4 PSNH--EVMPGGSVNLTCVAVGAPMPYVKWMKGGE--ELTKEDEMPVGRNVLELTNIY--ESANYTCVAISSLGMIEATA 77


                   ....*
gi 2217265341  592 RLEVK 596
Cdd:cd05739     78 QVTVK 82

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 1 (NCAM-1) and similar proteins; The members here are composed of the fourth immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule (NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-non-NCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions), through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain. Also included in this group is NCAM-2 (also known as OCAM/mamFas II and RNCAM) NCAM-2 is differentially expressed in the developing and mature olfactory epithelium (OE). One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 409395 [Multi-domain] Cd Length: 96 Bit Score: 39.43 E-value: 1.26e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217265341  343 LECIASGVPTPDIAWyKKGGDLPSDKAKFENFN---------KALRITNVSEEDSGEYFCLASNKMG 400
Cdd:cd05732     21 LTCEAEGDPIPEITW-RRATRGISFEEGDLDGRivvrgharvSSLTLKDVQLTDAGRYDCEASNRIG 86

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 1 (NCAM-1); The members here are composed of the fourth Ig domain of Neural Cell Adhesion Molecule 1(NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM) and heterophilic (NCAM-non-NCAM) interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions), through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain. One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 143277 [Multi-domain] Cd Length: 97 Bit Score: 39.58 E-value: 1.31e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217265341  343 LECIASGVPTPDIAWyKKGGDLPSDKAKFENFN---------KALRITNVSEEDSGEYFCLASNKMG 400
Cdd:cd05869     22 LTCEASGDPIPSITW-RTSTRNISSEEKTLDGHivvrsharvSSLTLKYIQYTDAGEYLCTASNTIG 87

C-terminal immunoglobulin (Ig)-like domain of M-protein; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of M-protein (also known as myomesin-2). M-protein is a structural protein localized to the M-band, a transverse structure in the center of the sarcomere, and is a candidate for M-band bridges. M-protein is modular consisting mainly of repetitive IG-like and fibronectin type III (FnIII) domains and has a muscle-type specific expression pattern. M-protein is present in fast fibers.

Pssm-ID: 143299 Cd Length: 92 Bit Score: 39.51 E-value: 1.31e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217265341  527 LDCPFFGSPIPTLRWFKNGQGSNLDGGNYHVYENG---SLEIKMIRKEDQGIYTCVATNILG 585
Cdd:cd05891     21 LTCTVFGNPDPEVIWFKNDQDIELSEHYSVKLEQGkyaSLTIKGVTSEDSGKYSINVKNKYG 82

Immunoglobulin I-set domain;

Pssm-ID: 400151 [Multi-domain] Cd Length: 90 Bit Score: 39.16 E-value: 1.33e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2217265341  224 LDPVVVQEGAPLTLQCNpPPGLPSPVIFWMSSSmEPITQDKRVSQGHNGDLYF---SNVMLQDMQTdYSCNA 292
Cdd:pfam07679    7 PKDVEVQEGESARFTCT-VTGTPDPEVSWFKDG-QPLRSSDRFKVTYEGGTYTltiSNVQPDDSGK-YTCVA 75

Third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM); The members here are composed of the third immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains, five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains the chicken neuron-glia cell adhesion molecule, Ng-CAM.

Pssm-ID: 409460 [Multi-domain] Cd Length: 83 Bit Score: 39.12 E-value: 1.43e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2217265341  527 LDCPFFGSPIPTLRWFKNGQGSNLDGGNYHvYENGSLEIKMIRKEDQGIYTCVATNILGKA 587
Cdd:cd05876     15 LECIAEGLPTPTVKWLRPSGPLPPDRVKYQ-NHNKTLQLLNVGESDDGEYVCLAENSLGSA 74

Second immunoglobulin (Ig)-like domain of protein tyrosine kinase (PTK) 7; The members here are composed of the second immunoglobulin (Ig)-like domain in protein tyrosine kinase (PTK) 7, also known as CCK4. PTK7 is a subfamily of the receptor protein tyrosine kinase family, and is referred to as an RPTK-like molecule. RPTKs transduce extracellular signals across the cell membrane and play important roles in regulating cell proliferation, migration, and differentiation. PTK7 is organized as an extracellular portion having seven Ig-like domains, a single transmembrane region, and a cytoplasmic tyrosine kinase-like domain. PTK7 is considered a pseudokinase as it has several unusual residues in some of the highly conserved tyrosine kinase (TK) motifs; it is predicted to lack TK activity. PTK7 may function as a cell-adhesion molecule. PTK7 mRNA is expressed at high levels in placenta, melanocytes, liver, lung, pancreas, and kidney. PTK7 is overexpressed in several cancers, including melanoma and colon cancer lines.

Pssm-ID: 409417 Cd Length: 95 Bit Score: 39.53 E-value: 1.43e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2217265341  524 RTRLDCPFFGSPIPTLRWFKNGQGSNLDGGNYHVY-ENGSLEIKMIRKEDQGIYTCVATNILGKA 587
Cdd:cd05760     18 RVTLRCHIDGHPRPTYQWFRDGTPLSDGQGNYSVSsKERTLTLRSAGPDDSGLYYCCAHNAFGSV 82

First immunoglobulin (Ig)-like domain in neogenin, and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain in neogenin and related proteins. Neogenin is a cell surface protein which is expressed in the developing nervous system of vertebrate embryos in the growing nerve cells. It is also expressed in other embryonic tissues and may play a general role in developmental processes such as cell migration, cell-cell recognition, and tissue growth regulation. Included in this group is the tumor suppressor protein DCC which is deleted in colorectal carcinoma. DCC and neogenin each have four Ig-like domains followed by six fibronectin type III domains, a transmembrane domain, and an intracellular domain. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409387 Cd Length: 97 Bit Score: 39.38 E-value: 1.63e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217265341  605 PEDQVARRGTTVQLECRVKHDPSLKltVSWLKDDEPLYIG---NRMKKEDDSLTIFGVAER-----DQGSYTCVASTE 674
Cdd:cd05722      8 PSDIVAMRGGPVVLNCSAESDPPPK--IEWKKDGVLLNLVsdeRRQQLPNGSLLITSVVHSkhnkpDEGFYQCVAQNE 83

Immunoglobulin I-set domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1); The members here are composed of the immunoglobulin I-set (IgI) domain of the Leucine-rich repeat and immunoglobin-like domain-containing protein 1 (Lingo-1). Human Lingo-1 is a central nervous system-specific transmembrane glycoprotein also known as LERN-1, which functions as a negative regulator of neuronal survival, axonal regeneration, and oligodendrocyte differentiation and myelination. Lingo-1 is a key component of the Nogo receptor signaling complex (RTN4R/NGFR) in RhoA activation responsible for some inhibition of axonal regeneration by myelin-associated factors. The ligand-binding ectodomain of human Lingo-1 contains a bimodular, kinked structure composed of leucine-rich repeat (LRR) and immunoglobulin (Ig)-like modules. Diseases associated with Lingo-1 include mental retardation, autosomal recessive 64 and essential tremor. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the Lingo-1 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409561 Cd Length: 92 Bit Score: 39.30 E-value: 1.63e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217265341  338 GMDLLLECIASGVPTPDIAWYKKGGDLPSDKAKFENF---NKALRITNVSEEDSGEYFCLASNKMGSIRHTISVRV 410
Cdd:cd20969     17 GHTVQFVCRADGDPPPAILWLSPRKHLVSAKSNGRLTvfpDGTLEVRYAQVQDNGTYLCIAANAGGNDSMPAHLHV 92

Second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor; member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin (Ig)-like domain of fibroblast growth factor (FGF) receptor. FGF receptors bind FGF signaling polypeptides. FGFs participate in multiple processes such as morphogenesis, development, and angiogenesis. FGFs bind to four FGF receptor tyrosine kinases (FGFR1, FGFR2, FGFR3, FGFR4). Receptor diversity is controlled by alternative splicing producing splice variants with different ligand binding characteristics and different expression patterns. FGFRs have an extracellular region comprised of three IG-like domains, a single transmembrane helix, and an intracellular tyrosine kinase domain. Ligand binding and specificity reside in the Ig-like domains 2 and 3, and the linker region that connects these two. FGFR activation and signaling depend on FGF-induced dimerization, a process involving cell surface heparin or heparin sulfate proteoglycans.

Pssm-ID: 409443 [Multi-domain] Cd Length: 95 Bit Score: 39.07 E-value: 1.77e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217265341  613 GTTVQLECRVKHDPslKLTVSWLKDDEPLYIGNRM-----KKEDDSLTIFGVAERDQGSYTCVASTE 674
Cdd:cd05857     19 ANTVKFRCPAAGNP--TPTMRWLKNGKEFKQEHRIggykvRNQHWSLIMESVVPSDKGNYTCVVENE 83

Third immunoglobulin (Ig)-like domain of fibroblast growth factor receptor (FGFR); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain of fibroblast growth factor receptor (FGFR). Fibroblast growth factors (FGFs) participate in morphogenesis, development, angiogenesis, and wound healing. These FGF-stimulated processes are mediated by four FGFR tyrosine kinases (FGRF1-4). FGFRs are comprised of an extracellular portion consisting of three Ig-like domains, a transmembrane helix, and a cytoplasmic portion having protein tyrosine kinase activity. The highly conserved Ig-like domains 2 and 3, and the linker region between D2 and D3 define a general binding site for FGFs. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409363 Cd Length: 102 Bit Score: 39.33 E-value: 1.87e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  605 PEDQVARRGTTVQLECRVKHDPslKLTVSWLKDDE----PLY------------IGNRMKKEDDSLTIFGVAERDQGSYT 668
Cdd:cd04974      8 PANQTVVLGSDVEFHCKVYSDA--QPHIQWLKHVEvngsKYGpdglpyvtvlkvAGVNTTGEENTLTISNVTFDDAGEYI 85

                           90
                   ....*....|....*..
gi 2217265341  669 CVASTELDQDLAKAYLT 685
Cdd:cd04974     86 CLAGNSIGLSFHSAWLT 102

C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin, and similar domains; member of the I-set IgSF domains; The members here are composed of the C-terminal immunoglobulin-like domain of the myosin-associated giant protein kinase Twitchin and similar proteins, including Caenorhabditis elegans and Aplysia californica Twitchin, Drosophila melanogaster Projectin, and similar proteins. These are very large muscle proteins containing multiple immunoglobulin (Ig)-like and fibronectin type III (FN3) domains and a single kinase domain near the C-terminus. In humans these proteins are called Titin. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The Ig-like domain of the Twitchin is a member of the I-set IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins (titin, telokin, and twitchin), the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D.

Pssm-ID: 409541 [Multi-domain] Cd Length: 89 Bit Score: 38.85 E-value: 1.95e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2217265341  611 RRGTTVQLECRVKHDPslKLTVSWLKDDEPLYIG----NRMKKEDDSLTIFGVAERDQGSYTCVA 671
Cdd:cd20949     12 KEGQSATILCEVKGEP--QPNVTWHFNGQPISASvadmSKYRILADGLLINKVTQDDTGEYTCRA 74

Immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM) and similar proteins; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of the L1 cell adhesion molecule (CAM). L1 belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region and an intracellular domain. L1 is primarily expressed in the nervous system and is involved in its development and function. L1 is associated with an X-linked recessive disorder, X-linked hydrocephalus, MASA syndrome, or spastic paraplegia type 1, that involves abnormalities of axonal growth. This group also contains NrCAM [Ng(neuronglia)CAM-related cell adhesion molecule], which is primarily expressed in the nervous system, and human neurofascin. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lacks a C" strand.

Pssm-ID: 409396 [Multi-domain] Cd Length: 94 Bit Score: 38.93 E-value: 1.97e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217265341  527 LDCPFFGSPIPTLRWFKNGQGSNLDGG-NYHVYEN-GSLEI--KMIRKED-QGIYTCVATNILGKA-ENQVRL 593
Cdd:cd05733     21 IKCEAKGNPQPTFRWTKDGKFFDPAKDpRVSMRRRsGTLVIdnHNGGPEDyQGEYQCYASNELGTAiSNEIRL 93

Second immunoglobulin (Ig)-like domain of interleukin-1 receptor (IL1R), and similar domains; The members here are composed of the second immunoglobulin (Ig)-like domain of interleukin-1 receptor (IL1R; also known as cluster of differentiation (CD) 121). IL-1 alpha and IL-1 beta are cytokines which participate in the regulation of inflammation, immune responses, and hematopoiesis. These cytokines bind to the IL-1 receptor type 1 (IL1R1), which is activated on additional association with interleukin-1 receptor accessory protein (IL1RAP). IL-1 also binds a second receptor designated type II (IL1R2). Mature IL1R1 consists of three IG-like domains, a transmembrane domain, and a large cytoplasmic domain. Mature IL1R2 is organized similarly except that it has a short cytoplasmic domain. The latter does not initiate signal transduction. A naturally occurring cytokine IL-1RA (IL-1 receptor antagonist) is widely expressed and binds to IL-1 receptors, inhibiting the binding of IL-1 alpha and IL-1 beta. This group also contains ILIR-like 1 (IL1R1L) which maps to the same chromosomal location as IL1R1 and IL1R2.

Pssm-ID: 409415 Cd Length: 92 Bit Score: 38.84 E-value: 1.97e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  352 TPDIAWYKkggdlpsDKAKFENFNK------ALRITNVSEEDSGEYFCLAS-NKMGSIRH---TISVRVK 411
Cdd:cd05757     29 LPPIQWYK-------DCKPLQGDKRfipkgsKLLIQNVTEEDAGNYTCKFTyTHNGKQYNvtrTISLTVT 91

Immunoglobulin Variable (IgV) domain in HERV-H LTR-associating 2 (HHLA2); The members here are composed of the immunoglobulin variable (IgV) region in HERV-H LTR-associating 2 (HHLA2; also known as B7-H7/B7 homolog 7). HHLA2 is a member of the B7 family of immune regulatory proteins. Mature human HHLA2 consists of an extracellular domain (ECD) with three immunoglobulin-like domains, a transmembrane segment, and a cytoplasmic domain. HHLA2 is widely expressed in human cancers including non-small cell lung carcinoma (NSCLS), triple negative breast cancer (TNBC), and melanoma, but has limited expression on normal tissues. Interestingly, unlike other members of B7 family, HHLA2 is not expressed in mice or rats. HHLA2 functions as a T cell coinhibitory molecules as it inhibits the proliferation of activated CD4(+) and CD8(+) T cells and their cytokine production. Furthermore, HHLA2 is constitutively expressed on the surface of human monocytes and is induced on B cells after stimulation, however it is not inducible on T cells.

Pssm-ID: 409512 Cd Length: 107 Bit Score: 39.29 E-value: 1.99e-03

                           10        20        30
                   ....*....|....*....|....*....|....*.
gi 2217265341  560 NGSLEIKMIRKEDQGIYTCVATNILGKAENQVRLEV 595
Cdd:cd16091     72 NASLLLRRVQLQDEGRYKCYTSTIIGNQESFVNLKV 107

Immunoglobulin V-set domain; This domain is found in antibodies as well as neural protein P0 and CTL4 amongst others.

Pssm-ID: 462230 Cd Length: 109 Bit Score: 39.36 E-value: 2.00e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  542 FKNGQGSNLDGGNYHV-----YENGSLEIKMIRKEDQGIYTC-VATNILGKAENQVRLEV 595
Cdd:pfam07686   49 YSNGSEEGVKKGRFSGrgdpsNGDGSLTIQNLTLSDSGTYTCaVIPSGEGVFGKGTRLTV 108

Second immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the second immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. DSCAM is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409545 Cd Length: 95 Bit Score: 39.06 E-value: 2.12e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  506 PPRMLSPRN-QLIRVILYNRTRLDCPFFGSPIPTLRWFKNGQGSNLDGG---NYHVYE-NGSLEIKMIRKEDQGIYTCVA 580
Cdd:cd20953      1 APKIPGLSKsQPLTVSSASSIALLCPAQGYPAPSFRWYKFIEGTTRKQAvvlNDRVKQvSGTLIIKDAVVEDSGKYLCVV 80


                   ....*
gi 2217265341  581 TNILG 585
Cdd:cd20953     81 NNSVG 85

Third immunoglobulin (Ig)-like domain of fibroblast growth factor receptor 2 (FGFR2); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin (Ig)-like domain of human fibroblast growth factor receptor 2 (FGFR2). Fibroblast growth factors (FGFs) participate in morphogenesis, development, angiogenesis, and wound healing. These FGF-stimulated processes are mediated by four FGFR tyrosine kinases (FGRF1-4). FGFRs are comprised of an extracellular portion consisting of three Ig-like domains, a transmembrane helix, and a cytoplasmic portion having protein tyrosine kinase activity. The highly conserved Ig-like domains 2 and 3, and the linker region between D2 and D3 define a general binding site for FGFs. FGFR2 is required for male sex determination. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409444 Cd Length: 105 Bit Score: 39.17 E-value: 2.25e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  328 GTASSQMVLRGMDLLLECIASGVPTPDIAWYK----KGGDLPSDKAKFENFNKA------------LRITNVSEEDSGEY 391
Cdd:cd05858      6 GLPANTSVVVGTDAEFVCKVYSDAQPHIQWLKhvekNGSKYGPDGLPYVEVLKTagvnttdkeievLYLRNVTFEDAGEY 85

                           90
                   ....*....|....
gi 2217265341  392 FCLASNKMGSIRHT 405
Cdd:cd05858     86 TCLAGNSIGISHHS 99

Immunoglobulin (Ig)-like variable (V) domain of the Signal-Regulatory Protein (SIRP); The members here are composed of the immunoglobulin (Ig)-like domain of the Signal-Regulatory Protein (SIRP). The SIRPs belong to the "paired receptors" class of membrane proteins that comprise several genes coding for proteins with similar extracellular regions, but very different transmembrane/cytoplasmic regions with different (activating or inhibitory) signaling potentials. They are commonly on NK cells, but are also on many myeloid cells. Their extracellular region contains three immunoglobulin superfamily domains, a single V-set, and two C1-set IgSF domains. Their cytoplasmic tails that contain either ITIMs or transmembrane regions have positively charged residues that allow an association with adaptor proteins, such as DAP12/KARAP, containing ITAMs. There are 3 distinct SIRP members: alpha, beta, and gamma. SIRP alpha (also known as CD172a or SRC homology 2 domain-containing protein tyrosine phosphatase substrate 1/Shps-1) is a membrane receptor that interacts with a ligand CD47 expressed on many cells and gives an inhibitory signal through immunoreceptor tyrosine-based inhibition motifs in the cytoplasmic region that interact with phosphatases SHP-1 and SHP-2. SIRP beta has a short cytoplasmic region and associates with a transmembrane adapter protein DAP12 containing immunoreceptor tyrosine-based activation motifs to give an activating signal. SIRP gamma contains a very short cytoplasmic region lacking obvious signaling motifs, but also binds CD47 with much less affinity. Members of this group contain standard Ig superfamily V-set AGFCC'C"/DEB domain topology.

Pssm-ID: 409516 Cd Length: 111 Bit Score: 39.08 E-value: 2.37e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  332 SQMVLRGMDLLLEC-IASGVPTPDIAWYK------------KGGDLP-----SDKAKFENFNKALRITNVSEEDSGEYFC 393
Cdd:cd16097      8 SVSVAAGESATLHCtVTSLIPVGPIQWFRgagpgreliynqKEGHFPrvttvSDLTKRNNMDFSIRISNITPADAGTYYC 87


                   ....*
gi 2217265341  394 LASNK 398
Cdd:cd16097     88 VKFRK 92

Second Ig-like domain of Junctional adhesion molecule-1 (JAM1); a member of the I-set of IgSF domains; The members here are composed of the second Ig-like domain of Junctional adhesion molecule-1 (JAM1). JAM1 is an immunoglobulin superfamily (IgSF) protein with two Ig-like domains in its extracellular region; it plays a role in the formation of endothelial and epithelial tight junction and acts as a receptor for mammalian reovirus sigma-1. The IgSF is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. The two sheets are linked together by a conserved disulfide bond between B strand and F strand. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. The second Ig-like domain of JAM1 is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, the A strand of the I-set is discontinuous but lacks a C" strand. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors.

Pssm-ID: 409542 Cd Length: 97 Bit Score: 38.84 E-value: 2.54e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  523 NRTRLDCPFF-GSPIPTLRWFKNGQGSNLDGGNYHVYEN---------GSLEIKMIRKEDQGIYTCVATNILGKAE--NQ 590
Cdd:cd20950     13 NRAVLTCSEPdGSPPSEYTWFKDGVVMPTNPKSTRAFSNssysldpttGELVFDPLSASDTGEYSCEARNGYGTPMrsNA 92


                   ....*
gi 2217265341  591 VRLEV 595
Cdd:cd20950     93 VRMEA 97

Fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; Members here are composed the fourth immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, Robo3), and three mammalian Slit homologs (Slit-1, Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, and Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409391 [Multi-domain] Cd Length: 98 Bit Score: 38.78 E-value: 2.56e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217265341  333 QMVLRGMDLLLECIASGVPTPDIAWYKKGGDL-------PSDKAKFENFNKA-LRITNVSEEDSGEYFCLASNKMGSI 402
Cdd:cd05726      9 QVVALGRTVTFQCETKGNPQPAIFWQKEGSQNllfpyqpPQPSSRFSVSPTGdLTITNVQRSDVGYYICQALNVAGSI 86

C-terminal immunoglobulin (Ig)-like domain of myotilin; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the C-terminal immunoglobulin (Ig)-like domain of myotilin. Mytolin belongs to the palladin-myotilin-myopalladin family. Proteins belonging to the latter family contain multiple Ig-like domains and function as scaffolds, modulating the actin cytoskeleton. Myotilin is most abundant in skeletal and cardiac muscle and is involved in maintaining sarcomere integrity. It binds to alpha-actinin, filamin, and actin. Mutations in myotilin lead to muscle disorders. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409473 Cd Length: 92 Bit Score: 38.60 E-value: 2.78e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  513 RNQLIRVILYNRTRLDCPFFGSPIPTLRWFKNGQGSNLDGGNYHVYENGS----LEIKMIRKEDQGIYTCVATNILGKAE 588
Cdd:cd05892      6 KPQNKKVLEGDPVRLECQISAIPPPQIFWKKNNEMLQYNTDRISLYQDNCgricLLIQNANKKDAGWYTVSAVNEAGVVS 85


                   ....*..
gi 2217265341  589 NQVRLEV 595
Cdd:cd05892     86 CNARLDV 92

Immunoglobulin (Ig)-like domain of human neurofascin (NF); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of human neurofascin (NF). NF belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region, and a cytoplasmic domain. NF has many alternatively spliced isoforms having different temporal expression patterns during development. NF participates in axon subcellular targeting and synapse formation, however little is known of the functions of the different isoforms. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lacks a C" strand.

Pssm-ID: 409459 Cd Length: 95 Bit Score: 38.42 E-value: 2.84e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  509 MLSPRNQLIrvilynrtrLDCPFFGSPIPTLRWFKNGQGSNL--DGGNYHVYENGSLEIKMI---RKED-QGIYTCVATN 582
Cdd:cd05875     12 IVDPRDNIL---------IECEAKGNPVPTFHWTRNGKFFNVakDPRVSMRRRSGTLVIDFRgggRPEDyEGEYQCFARN 82

                           90
                   ....*....|...
gi 2217265341  583 ILGKA-ENQVRLE 594
Cdd:cd05875     83 KFGTAlSNKIRLQ 95

Fourth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409548 [Multi-domain] Cd Length: 96 Bit Score: 38.31 E-value: 2.88e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217265341  424 ILAPGEDGRLVCRANGNPKPTVQWMVNGEPLqsaPPNPNREVaGDTIIFRDTQIS----SRA------VYQCNTSNEHG 492
Cdd:cd20956     12 TLQPGPSVSLKCVASGNPLPQITWTLDGFPI---PESPRFRV-GDYVTSDGDVVSyvniSSVrvedggEYTCTATNDVG 86

Second immunoglobulin (Ig)-like domain of Axl/Tyro3 family receptor tyrosine kinases (RTKs); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in the Axl/Tyro3 family of receptor tyrosine kinases (RTKs). This family includes Axl (also known as Ark, Ufo, and Tyro7), Tyro3 (also known as Sky, Rse, Brt, Dtk, and Tif), and Mer (also known as Nyk, c-Eyk, and Tyro12). Axl/Tyro3 family receptors have an extracellular portion with two Ig-like domains followed by two fibronectin-types III (FNIII) domains, a membrane-spanning single helix, and a cytoplasmic tyrosine kinase domain. Axl, Tyro3, and Mer are widely expressed in adult tissues, though they show higher expression in the brain, lymphatic and vascular systems, and testis. Axl, Tyro3, and Mer bind the vitamin K dependent protein Gas6 with high affinity, and in doing so activate their tyrosine kinase activity. Axl/Gas6 signaling may play a part in cell adhesion processes, prevention of apoptosis, and cell proliferation.

Pssm-ID: 409407 Cd Length: 82 Bit Score: 38.22 E-value: 2.90e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  415 YWLDEPKNLILAPGEDGRLVCRANGNPKP-TVQWMVNGEPLQSAP-PNPNrevagdtiIFRDTQISSRAVYQCNTSNEHG 492
Cdd:cd05749      1 HFTVEPEDLAVTANTPFNLTCQAVGPPEPvEILWWQGGSPLGGPPaPSPS--------VLNVPGLNETTKFSCEAHNAKG 72

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

Pssm-ID: 464026 [Multi-domain] Cd Length: 79 Bit Score: 38.14 E-value: 2.91e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217265341  424 ILAPGEDGRLVCRANGNPKPTVQWMVNGEPLqsaPPNPNrevagdtIIFRDTQISSRAVYQCNTSNEHG 492
Cdd:pfam13895   10 VVTEGEPVTLTCSAPGNPPPSYTWYKDGSAI---SSSPN-------FFTLSVSAEDSGTYTCVARNGRG 68

Third immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the third immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143222 [Multi-domain] Cd Length: 74 Bit Score: 38.00 E-value: 3.08e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217265341  140 CEAKGNPAPSFHWTRNSRffniakdpRVSMRRR-----SGTLvidfRSGGRPEEYEGEYQCFARNKFGT 203
Cdd:cd05745      9 CEAQGYPQPVIAWTKGGS--------QLSVDRRhlvlsSGTL----RISRVALHDQGQYECQAVNIVGS 65

First immunoglobulin (Ig) domain of contactin-1; member of the I-set of Ig superfamily domains; The members here are composed of the first immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may, through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma. This group belongs to the I-set of IgSF domains.

Pssm-ID: 409436 [Multi-domain] Cd Length: 95 Bit Score: 38.40 E-value: 3.18e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217265341  524 RTRLDCPFFGSPIPTLRWFKNGQGSNLDGGNYHVYeNGSLEIKMIRK-EDQGIYTCVATNILGK 586
Cdd:cd05849     21 KVSVNCRARANPFPIYKWRKNNLDIDLTNDRYSMV-GGNLVINNPDKyKDAGRYVCIVSNIYGK 83

Immunoglobulin (Ig)-like domain in neuregulins; The members here are composed of the immunoglobulin (Ig)-like domain in neuregulins (NRGs). NRGs are signaling molecules which participate in cell-cell interactions in the nervous system, breast, heart, and other organ systems, and are implicated in the pathology of diseases including schizophrenia, multiple sclerosis, and breast cancer. There are four members of the neuregulin gene family (NRG-1, NRG-2, NRG-3, and NRG-4). The NRG-1 protein, binds to and activates the tyrosine kinases receptors ErbB3 and ErbB4, initiating signaling cascades. The other NRGs proteins bind one or the other or both of these ErbBs. NRG-1 has multiple functions: in the brain it regulates various processes such as radial glia formation and neuronal migration, dendritic development, and expression of neurotransmitters receptors, while in the peripheral nervous system NRG-1 regulates processes such as target cell differentiation, and Schwann cell survival. There are many NRG-1 isoforms which arise from the alternative splicing of mRNA. Less is known of the functions of the other NRGs. NRG-2 and NRG-3 are expressed predominantly in the nervous system. NRG-2 is expressed by motor neurons and terminal Schwann cells, and is concentrated near synaptic sites and may be a signal that regulates synaptic differentiation. NRG-4 has been shown to direct pancreatic islet cell development towards the delta-cell lineage.

Pssm-ID: 409408 [Multi-domain] Cd Length: 92 Bit Score: 38.26 E-value: 3.23e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  126 KDHIVDPRDNILIECEAKG-NPAPSFHWTRNSRFFNIAKDPRVSMRRRSGTLVIDFRSGGRpeEYEGEYQCFARNKFGTA 204
Cdd:cd05750      7 KSQTVQEGSKLVLKCEATSeNPSPRYRWFKDGKELNRKRPKNIKIRNKKKNSELQINKAKL--EDSGEYTCVVENILGKD 84


                   ....*....
gi 2217265341  205 lSNRIRLQV 213
Cdd:cd05750     85 -TVTGNVTV 92

Immunoglobulin domain; This domain contains immunoglobulin-like domains.

Pssm-ID: 464026 [Multi-domain] Cd Length: 79 Bit Score: 37.76 E-value: 3.44e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 2217265341  605 PEDQVARRGTTVQLECRVKHDPSLKltVSWLKDDEPLyignrmkKEDDSLTIFGVAERDQGSYTCVAS 672
Cdd:pfam13895    6 PSPTVVTEGEPVTLTCSAPGNPPPS--YTWYKDGSAI-------SSSPNFFTLSVSAEDSGTYTCVAR 64

Immunoglobulin (Ig)-like domain of human neurofascin (NF); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the first immunoglobulin (Ig)-like domain of human neurofascin (NF). NF belongs to the L1 subfamily of cell adhesion molecules (CAMs) and is comprised of an extracellular region having six Ig-like domains and five fibronectin type III domains, a transmembrane region, and a cytoplasmic domain. NF has many alternatively spliced isoforms having different temporal expression patterns during development. NF participates in axon subcellular targeting and synapse formation, however little is known of the functions of the different isoforms. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lacks a C" strand.

Pssm-ID: 409459 Cd Length: 95 Bit Score: 38.42 E-value: 3.52e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  421 KNLILAPGEDGRLVCRANGNPKPTVQWMVNGEPLQSA--PPNPNREVAGDTIIfrDTQISSR-----AVYQCNTSNEHGY 493
Cdd:cd05875      9 KDYIVDPRDNILIECEAKGNPVPTFHWTRNGKFFNVAkdPRVSMRRRSGTLVI--DFRGGGRpedyeGEYQCFARNKFGT 86


                   ....
gi 2217265341  494 LLAN 497
Cdd:cd05875     87 ALSN 90

First immunoglobulin-like domains A168 within the A-band segment of human cardiac titin, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the first immunoglobulin-like domain A168 within the A-band segment of human cardiac titin. Titin is a key component in the assembly and functioning of vertebrate striated muscles. By providing connections at the level of individual microfilaments, it contributes to the fine balance of forces between the two halves of the sarcomere. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structures of the titin-A168169 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409563 Cd Length: 93 Bit Score: 38.22 E-value: 3.60e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217265341  338 GMDLLLECIASGVPTPDIAWYKKGGDLPSDKAKFENFNK----ALRITNVS-EEDSGEYFCLASNKMGS 401
Cdd:cd20971     16 QSNATLVCKVTGHPKPIVKWYRQGKEIIADGLKYRIQEFkggyHQLIIASVtDDDATVYQVRATNQGGS 84

Immunoglobulin (Ig)-like domain in neuregulins; The members here are composed of the immunoglobulin (Ig)-like domain in neuregulins (NRGs). NRGs are signaling molecules which participate in cell-cell interactions in the nervous system, breast, heart, and other organ systems, and are implicated in the pathology of diseases including schizophrenia, multiple sclerosis, and breast cancer. There are four members of the neuregulin gene family (NRG-1, NRG-2, NRG-3, and NRG-4). The NRG-1 protein, binds to and activates the tyrosine kinases receptors ErbB3 and ErbB4, initiating signaling cascades. The other NRGs proteins bind one or the other or both of these ErbBs. NRG-1 has multiple functions: in the brain it regulates various processes such as radial glia formation and neuronal migration, dendritic development, and expression of neurotransmitters receptors, while in the peripheral nervous system NRG-1 regulates processes such as target cell differentiation, and Schwann cell survival. There are many NRG-1 isoforms which arise from the alternative splicing of mRNA. Less is known of the functions of the other NRGs. NRG-2 and NRG-3 are expressed predominantly in the nervous system. NRG-2 is expressed by motor neurons and terminal Schwann cells, and is concentrated near synaptic sites and may be a signal that regulates synaptic differentiation. NRG-4 has been shown to direct pancreatic islet cell development towards the delta-cell lineage.

Pssm-ID: 409408 [Multi-domain] Cd Length: 92 Bit Score: 37.88 E-value: 3.93e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  608 QVARRGTTVQLECR-VKHDPSLKLtvSWLKD------DEPLYIGNRMKKEDDSLTIFGVAERDQGSYTCVASTELDQDLA 680
Cdd:cd05750      9 QTVQEGSKLVLKCEaTSENPSPRY--RWFKDgkelnrKRPKNIKIRNKKKNSELQINKAKLEDSGEYTCVVENILGKDTV 86


                   ....*.
gi 2217265341  681 KAYLTV 686
Cdd:cd05750     87 TGNVTV 92

Second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig)-like domain in Robo (roundabout) receptors. Robo receptors play a role in the development of the central nervous system (CNS), and are receptors of the Slit protein. Slit is a repellant secreted by the neural cells in the midline. Slit acts through Robo to prevent most neurons from crossing the midline from either side. Three mammalian Robo homologs (Robo1, Robo2, and Robo3), and three mammalian Slit homologs (Slit-1,Slit-2, Slit-3), have been identified. Commissural axons, which cross the midline, express low levels of Robo; longitudinal axons, which avoid the midline, express high levels of Robo. Robo1, Robo2, and Robo3 are expressed by commissural neurons in the vertebrate spinal cord and Slit-1, Slit-2, Slit-3 are expressed at the ventral midline. Robo-3 is a divergent member of the Robo family which instead of being a positive regulator of Slit responsiveness, antagonizes Slit responsiveness in precrossing axons. The Slit-Robo interaction is mediated by the second leucine-rich repeat (LRR) domain of Slit and the two N-terminal Ig domains of Robo, Ig1 and Ig2. The primary Robo binding site for Slit-2 has been shown by surface plasmon resonance experiments and mutational analysis to be the Ig1 domain, while the Ig2 domain has been proposed to harbor a weak secondary binding site. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409389 [Multi-domain] Cd Length: 87 Bit Score: 37.77 E-value: 4.04e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 2217265341  137 LIECEA-KGNPAPSFHWTRNSRFFNIaKDPRVSMRRrSGTLVIDfrsggRPEEY-EGEYQCFARNKFGTALSNRIRLQV 213
Cdd:cd05724     16 VLECSPpRGHPEPTVSWRKDGQPLNL-DNERVRIVD-DGNLLIA-----EARKSdEGTYKCVATNMVGERESRAARLSV 87

CH3 domain (third constant Ig domain of the heavy chain) in immunoglobulin heavy alpha, gamma, and delta chains, and CH4 domain (fourth constant Ig domain of the heavy chain) in immunoglobulin heavy alpha, epsilon, and mu chains; member of the C1-set of I; The members here are composed of the third and fourth immunoglobulin constant domain (IgC) of alpha, delta, gamma and alpha, epsilon, and mu heavy chains, respectively. This domain is found on the Fc fragment. The basic structure of Ig molecules is a tetramer of two light chains and two heavy chains linked by disulfide bonds. There are two types of light chains: kappa and lambda; each is composed of a constant domain and a variable domain. There are five types of heavy chains: alpha, delta, epsilon, gamma, and mu, all consisting of a variable domain (VH) with three (alpha, delta and gamma) or four (epsilon and mu) constant domains (CH1 to CH4). Ig molecules are modular proteins, in which the variable and constant domains have clear, conserved sequence patterns.

Pssm-ID: 409425 Cd Length: 105 Bit Score: 38.09 E-value: 4.34e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  605 PEDQVARRgTTVQLECRVK-HDPSlKLTVSWLKDDEPL----YIGNRMKKEDDS-------LTIfGVAERDQG-SYTCVA 671
Cdd:cd05768      9 PEEELSLN-ETVTLTCLVKgFYPE-DIFVSWLQNGEPLpsadYKTTAPVPESDGsffvyskLNV-STADWNSGdVFSCVV 85


                   ...
gi 2217265341  672 STE 674
Cdd:cd05768     86 GHE 88

Immunoglobulin-like domain of human Aortic Preferentially Expressed Protein-1 (APEG-1) and similar proteins; a member of the I-set of IgSF domains; The members here are composed of the immunoglobulin I-set (IgI) domain of the Human Aortic Preferentially Expressed Protein-1 (APEG-1) and similar proteins. APEG-1 is a novel specific smooth muscle differentiation marker predicted to play a role in the growth and differentiation of arterial smooth muscle cells (SMCs). The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the human APEG-1 lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409567 Cd Length: 91 Bit Score: 37.83 E-value: 5.07e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 2217265341  533 GSPIPTLRWFKNGQGSNLDGGNY-HVYENGSLEIKMIRKE--DQGIYTCVATNILGKAENQVRLEV 595
Cdd:cd20975     26 GEPKPVVSWLRNRQPVRPDQRRFaEEAEGGLCRLRILAAErgDAGFYTCKAVNEYGARQCEARLEV 91

Immunoglobulin (Ig)-like I-set domain of Neural Cell Adhesion Molecule 1 (NCAM-1) and similar proteins; The members here are composed of the fourth immunoglobulin (Ig)-like domain of Neural Cell Adhesion Molecule (NCAM-1). NCAM plays important roles in the development and regeneration of the central nervous system, in synaptogenesis and neural migration. NCAM mediates cell-cell and cell-substratum recognition and adhesion via homophilic (NCAM-NCAM), and heterophilic (NCAM-non-NCAM), interactions. NCAM is expressed as three major isoforms having different intracellular extensions. The extracellular portion of NCAM has five N-terminal Ig-like domains and two fibronectin type III domains. The double zipper adhesion complex model for NCAM homophilic binding involves Ig1, Ig2, and Ig3. By this model, Ig1 and Ig2 mediate dimerization of NCAM molecules situated on the same cell surface (cis interactions), and Ig3 domains mediate interactions between NCAM molecules expressed on the surface of opposing cells (trans interactions), through binding to the Ig1 and Ig2 domains. The adhesive ability of NCAM is modulated by the addition of polysialic acid chains to the fifth Ig-like domain. Also included in this group is NCAM-2 (also known as OCAM/mamFas II and RNCAM) NCAM-2 is differentially expressed in the developing and mature olfactory epithelium (OE). One of the unique features of I-set domains is the lack of a C" strand. The structures of this group show that the Ig domain lacks this strand and thus is a member of the I-set of Ig domains.

Pssm-ID: 409395 [Multi-domain] Cd Length: 96 Bit Score: 37.89 E-value: 5.18e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217265341  134 DNILIECEAKGNPAPSFHWTRNSR-FFNIAKDP--RVSMRRRSG----TLV-IDFRSGGRpeeyegeYQCFARNKFG 202
Cdd:cd05732     17 EQITLTCEAEGDPIPEITWRRATRgISFEEGDLdgRIVVRGHARvsslTLKdVQLTDAGR-------YDCEASNRIG 86

Fourth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fourth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409548 [Multi-domain] Cd Length: 96 Bit Score: 37.54 E-value: 5.38e-03

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  117 PPTItKQSAKDHIVDPRDNILIECEAKGNPAPSFHWTRNSrfFNIAKDPRVSM---RRRSGTLV----IdfrSGGRPEEy 189
Cdd:cd20956      1 APVL-LETFSEQTLQPGPSVSLKCVASGNPLPQITWTLDG--FPIPESPRFRVgdyVTSDGDVVsyvnI---SSVRVED- 73

                           90       100
                   ....*....|....*....|....
gi 2217265341  190 EGEYQCFARNKFGTAlSNRIRLQV 213
Cdd:cd20956     74 GGEYTCTATNDVGSV-SHSARINV 96

Immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 2 (VEGFR-2); member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 2 (VEGFR-2). The VEGFRs have an extracellular component with seven Ig-like domains, a transmembrane segment, and an intracellular tyrosine kinase domain interrupted by a kinase-insert domain. VEGFRs bind VEGFs with high affinity at the Ig-like domains. VEGFR-2 (KDR/Flk-1) is a major mediator of the mitogenic, angiogenic and microvascular permeability-enhancing effects of VEGF-A; VEGF-A is important to the growth and maintenance of vascular endothelial cells and to the development of new blood- and lymphatic-vessels in physiological and pathological states. VEGF-A also interacts with VEGFR-1, which it binds more strongly than VEGFR-2. VEGFR-1 and VEGFR-2 may mediate a chemotactic and a survival signal in hematopoietic stem cells or leukemia cells. This group belongs to the I-set of IgSF domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand, but lack a C" strand.

Pssm-ID: 409450 Cd Length: 89 Bit Score: 37.60 E-value: 5.70e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 2217265341  349 GVPTPDIAWYKKGGDLPSDKAKFENFnkALRITNVSEEDSGEYFCLASNKMGSI--RHTISVRV 410
Cdd:cd05864     28 GYPPPEIKWYKNGIPIESNHTIKAGH--VLTIMEVTEKDAGNYTVVLTNPISKEkqRHTFSLVV 89

Second immunoglobulin (Ig)-like domain of interleukin-1 receptor (IL1R), and similar domains; The members here are composed of the second immunoglobulin (Ig)-like domain of interleukin-1 receptor (IL1R; also known as cluster of differentiation (CD) 121). IL-1 alpha and IL-1 beta are cytokines which participate in the regulation of inflammation, immune responses, and hematopoiesis. These cytokines bind to the IL-1 receptor type 1 (IL1R1), which is activated on additional association with interleukin-1 receptor accessory protein (IL1RAP). IL-1 also binds a second receptor designated type II (IL1R2). Mature IL1R1 consists of three IG-like domains, a transmembrane domain, and a large cytoplasmic domain. Mature IL1R2 is organized similarly except that it has a short cytoplasmic domain. The latter does not initiate signal transduction. A naturally occurring cytokine IL-1RA (IL-1 receptor antagonist) is widely expressed and binds to IL-1 receptors, inhibiting the binding of IL-1 alpha and IL-1 beta. This group also contains ILIR-like 1 (IL1R1L) which maps to the same chromosomal location as IL1R1 and IL1R2.

Pssm-ID: 409415 Cd Length: 92 Bit Score: 37.69 E-value: 5.88e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2217265341  512 PRNQLIRVILYNRtRLDCP-----FFGSPIPTLRWFKNGQGsnLDGGNYHVYENGSLEIKMIRKEDQGIYTCVAT 581
Cdd:cd05757      1 PRYKQKLPITKGG-KITCPdlddyKNENVLPPIQWYKDCKP--LQGDKRFIPKGSKLLIQNVTEEDAGNYTCKFT 72

Fifth immunoglobulin domain of the Drosophila melanogaster Dscam protein, and similar domains; a member of the I-set of IgSF domains; The members here are composed of the fifth immunoglobulin domain of the Drosophila melanogaster Down syndrome cell adhesion molecule (DSCAM) protein and similar proteins. Down syndrome cell adhesion molecule (DSCAM) is a cell adhesion molecule that plays critical roles in neural development, including axon guidance and branching, axon target recognition, self-avoidance and synaptic formation. DSCAM belongs to the immunoglobulin superfamily and contributes to defects in the central nervous system in Down syndrome patients. Vertebrate DSCAMs differ from Drosophila Dscam1 in that they lack the extensive alternative splicing that occurs in the insect gene. Drosophila melanogaster Dscam has 38,016 isoforms generated by the alternative splicing of four variable exon clusters, which allows every neuron in the fly to display a distinctive set of Dscam proteins on its cell surface. Drosophila Dscam1 is a cell-surface protein that plays important roles in neural development and axon tiling of neurons. It is shown that thousands of isoforms bind themselves through specific homophilic (self-binding) interactions, a process which mediates cellular self-recognition. Drosophila Dscam2 is also alternatively spliced and plays a key role in the development of two visual system neurons, monopolar cells L1 and L2. This group is a member of the I-set Ig domains, having A-B-E-D strands in one beta-sheet and A'-G-F-C-C' in the other. Like the V-set Ig domains, members of the I-set have a discontinuous A strand but lack a C" strand.

Pssm-ID: 409550 [Multi-domain] Cd Length: 89 Bit Score: 37.16 E-value: 6.41e-03

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2217265341  613 GTTVQLECRVKHDPsLKlTVSWLKDDEPLYIGNRMK-KEDDSLTIFGV-AERDQGSYTCVA 671
Cdd:cd20958     15 GQTLRLHCPVAGYP-IS-SITWEKDGRRLPLNHRQRvFPNGTLVIENVqRSSDEGEYTCTA 73

Third immunoglobulin (Ig)-like domain of peroxidasin; The members here are composed of the third immunoglobulin (Ig)-like domain in peroxidasin. Peroxidasin has a peroxidase domain and interacting extracellular motifs containing four Ig-like domains. It has been suggested that peroxidasin is secreted and has functions related to the stabilization of the extracellular matrix. It may play a part in various other important processes such as removal and destruction of cells which have undergone programmed cell death and protection of the organism against non-self.

Pssm-ID: 143222 [Multi-domain] Cd Length: 74 Bit Score: 36.84 E-value: 6.50e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 2217265341  613 GTTVQLECRVKHDPslKLTVSWLKDDEPLYIGNR-MKKEDDSLTIFGVAERDQGSYTCVASTELDQDLAKAYLTV 686
Cdd:cd05745      2 GQTVDFLCEAQGYP--QPVIAWTKGGSQLSVDRRhLVLSSGTLRISRVALHDQGQYECQAVNIVGSQRTVAQLTV 74

Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.

Pssm-ID: 395002 Cd Length: 86 Bit Score: 37.17 E-value: 6.84e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 2217265341  226 PVVVQEGAPLTLQCNPPPGLPSPVIFWMSSSMEPITQDKRV---SQGHNGDLYFSNVMLQDMQTdYSCNARFH 295
Cdd:pfam00047    5 TVTVLEGDSATLTCSASTGSPGPDVTWSKEGGTLIESLKVKhdnGRTTQSSLLISNVTKEDAGT-YTCVVNNP 76

Second immunoglobulin (Ig)-like domain of interleukin-1 receptor (IL1R), and similar domains; The members here are composed of the second immunoglobulin (Ig)-like domain of interleukin-1 receptor (IL1R; also known as cluster of differentiation (CD) 121). IL-1 alpha and IL-1 beta are cytokines which participate in the regulation of inflammation, immune responses, and hematopoiesis. These cytokines bind to the IL-1 receptor type 1 (IL1R1), which is activated on additional association with interleukin-1 receptor accessory protein (IL1RAP). IL-1 also binds a second receptor designated type II (IL1R2). Mature IL1R1 consists of three IG-like domains, a transmembrane domain, and a large cytoplasmic domain. Mature IL1R2 is organized similarly except that it has a short cytoplasmic domain. The latter does not initiate signal transduction. A naturally occurring cytokine IL-1RA (IL-1 receptor antagonist) is widely expressed and binds to IL-1 receptors, inhibiting the binding of IL-1 alpha and IL-1 beta. This group also contains ILIR-like 1 (IL1R1L) which maps to the same chromosomal location as IL1R1 and IL1R2.

Pssm-ID: 409415 Cd Length: 92 Bit Score: 37.30 E-value: 6.87e-03

                           10        20        30        40
                   ....*....|....*....|....*....|....*....|....*...
gi 2217265341  625 DPSLKLTVSWLKDDEPLYIGNRMKKEDDSLTIFGVAERDQGSYTCVAS 672
Cdd:cd05757     25 NENVLPPIQWYKDCKPLQGDKRFIPKGSKLLIQNVTEEDAGNYTCKFT 72

Fifth immunoglobulin (Ig) domain of contactin-1; The members here are composed of the fifth immunoglobulin (Ig) domain of the neural cell adhesion molecule contactin-1. Contactins are comprised of six Ig domains followed by four fibronectin type III (FnIII) domains anchored to the membrane by glycosylphosphatidylinositol. Contactin-1 is differentially expressed in tumor tissues and may through a RhoA mechanism, facilitate invasion and metastasis of human lung adenocarcinoma.

Pssm-ID: 409438 Cd Length: 89 Bit Score: 37.29 E-value: 7.13e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2217265341  337 RGMDLLLECIASGVPTPDIAWyKKGGDLPSDKAKFENFNK-ALRITNVSEEDSGEYFCLASNKMGSIRHT 405
Cdd:cd05852     16 KGGRVIIECKPKAAPKPKFSW-SKGTELLVNNSRISIWDDgSLEILNITKLDEGSYTCFAENNRGKANST 84

agrin-responsive second immunoglobulin-like domains (Ig2) of the Muscle-specific kinase (MuSK) ectodomain; a member of the I-set of Ig superfamily domains; The members here are composed of the second immunoglobulin-like (Ig) domains of the Muscle-specific kinase (MuSK) ectodomain. MuSK is a receptor tyrosine kinase specifically expressed in skeletal muscle, where it plays a central role in the formation and maintenance of the neuromuscular junction (NMJ). MuSK is activated by agrin, a neuron-derived heparan sulfate proteoglycan. The activation of MUSK in myotubes regulates the formation of NMJs through the regulation of different processes including the specific expression of genes in subsynaptic nuclei, the reorganization of the actin cytoskeleton and the clustering of the acetylcholine receptors (AChR) in the postsynaptic membrane. The Ig superfamily (IgSF) is a heterogenous group of proteins, built on a common fold comprised of a sandwich of two beta sheets. IgSF domains can be divided into 4 main classes based on their structures and sequences: the Variable (V), Constant 1 (C1), Constant 2 (C2), and Intermediate (I) sets. Unlike the V-set, one of the distinctive features of I-set domains is the lack of a C" strand. The structure of the MuSK lacks this strand and thus it belongs to the I-set of the IgSF. I-set domains are found in several cell adhesion molecules (such as VCAM, ICAM, and MADCAM), and are also present in numerous other diverse protein families, including several tyrosine-protein kinase receptors, the hemolymph protein hemolin, the muscle proteins titin, telokin, and twitchin, the neuronal adhesion molecule axonin-1, and the signaling molecule semaphorin 4D that is involved in axonal guidance, immune function and angiogenesis.

Pssm-ID: 409560 [Multi-domain] Cd Length: 88 Bit Score: 37.22 E-value: 7.58e-03

                           10        20        30        40        50        60        70
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 2217265341  600 RIYRMPEDQVARRGTTVQLECRVKHDPslKLTVSWLKDDEPLYIGNRMKK-EDDSLTIFGVAERDQGSYTCVASTEL 675
Cdd:cd20968      1 KITRPPTNVTIIEGLKAVLPCTTMGNP--KPSVSWIKGDDLIKENNRIAVlESGSLRIHNVQKEDAGQYRCVAKNSL 75