MAEBL; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364    5 SQKAEIKEMLASDDEEESSPKIEKAYVPKLTGTVKGKFDEMEKhRQEEQRKRTEEERKRRIEQDLLEKRKIQRELAKRAE 84
Cdd:PTZ00121 1356 ADEAEAAEEKAEAAEKKKEEAKKKADAAKKKAEEKKKADEAKK-KAEEDKKKADELKKAAAAKKKADEAKKKAEEKKKAD 1434

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364   85 QegddsllitvvpaksyktpGKTKDPEDLDREEGNGRTnheEDKMRYEEECRVLKEAKCLSLVMDDETEAKKEShfpgKL 164
Cdd:PTZ00121 1435 E-------------------AKKKAEEAKKADEAKKKA---EEAKKAEEAKKKAEEAKKADEAKKKAEEAKKAD----EA 1488

                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364  165 KSTFEELERQRQENRKKQAEEEARRRLEEERRSFEEARRHMVNEE---DENQDRETVFKEYRPGKLKLSFEEIERQRRED 241
Cdd:PTZ00121 1489 KKKAEEAKKKADEAKKAAEAKKKADEAKKAEEAKKADEAKKAEEAkkaDEAKKAEEKKKADELKKAEELKKAEEKKKAEE 1568

                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364  242 EKRKAEEEARRRIEEEKAAFAEARRSMVLDDDSPEIYKTVSQESLTPGKLEINFEQLlrqKMEEERRRTEEERRHKLEME 321
Cdd:PTZ00121 1569 AKKAEEDKNMALRKAEEAKKAEEARIEEVMKLYEEEKKMKAEEAKKAEEAKIKAEEL---KKAEEEKKKVEQLKKKEAEE 1645

                         330       340       350       360       370       380       390       400
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364  322 KQEFEQLRQE-----MGKEEEENESFGLSREYEELIKLKRSGSIQAKNLKSKFE---KIGQLSEKEVQKKIEEERAKRRA 393
Cdd:PTZ00121 1646 KKKAEELKKAeeenkIKAAEEAKKAEEDKKKAEEAKKAEEDEKKAAEALKKEAEeakKAEELKKKEAEEKKKAEELKKAE 1725

                         410       420
                  ....*....|....*....|....*...
gi 755504364  394 IDLEIKEREAENFHEDDDVDVRPAKKSE 421
Cdd:PTZ00121 1726 EENKIKAEEAKKEAEEDKKKAEEAKKDE 1753

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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364 499 PWFKKPLRNTSVVDSEPVRFTVKVTGEPKPEITWWFEGEILQ---DGEDYQYIERGETYCLYLPETFPEDGGEYMCKAVN 575
Cdd:cd20951    1 PEFIIRLQSHTVWEKSDAKLRVEVQGKPDPEVKWYKNGVPIDpssIPGKYKIESEYGVHVLHIRRVTVEDSAVYSAVAKN 80

                         90
                 ....*....|....
gi 755504364 576 NKGSAASTCILTIE 589
Cdd:cd20951   81 IHGEASSSASVVVE 94

MAEBL; Provisional

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364    5 SQKAEIKEMLASDDEEESSPKIEKAYVPKLTGTVKGKFDEMEKhRQEEQRKRTEEERKRRIEQDLLEKRKIQRELAKRAE 84
Cdd:PTZ00121 1356 ADEAEAAEEKAEAAEKKKEEAKKKADAAKKKAEEKKKADEAKK-KAEEDKKKADELKKAAAAKKKADEAKKKAEEKKKAD 1434

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364   85 QegddsllitvvpaksyktpGKTKDPEDLDREEGNGRTnheEDKMRYEEECRVLKEAKCLSLVMDDETEAKKEShfpgKL 164
Cdd:PTZ00121 1435 E-------------------AKKKAEEAKKADEAKKKA---EEAKKAEEAKKKAEEAKKADEAKKKAEEAKKAD----EA 1488

                         170       180       190       200       210       220       230       240
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364  165 KSTFEELERQRQENRKKQAEEEARRRLEEERRSFEEARRHMVNEE---DENQDRETVFKEYRPGKLKLSFEEIERQRRED 241
Cdd:PTZ00121 1489 KKKAEEAKKKADEAKKAAEAKKKADEAKKAEEAKKADEAKKAEEAkkaDEAKKAEEKKKADELKKAEELKKAEEKKKAEE 1568

                         250       260       270       280       290       300       310       320
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364  242 EKRKAEEEARRRIEEEKAAFAEARRSMVLDDDSPEIYKTVSQESLTPGKLEINFEQLlrqKMEEERRRTEEERRHKLEME 321
Cdd:PTZ00121 1569 AKKAEEDKNMALRKAEEAKKAEEARIEEVMKLYEEEKKMKAEEAKKAEEAKIKAEEL---KKAEEEKKKVEQLKKKEAEE 1645

                         330       340       350       360       370       380       390       400
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364  322 KQEFEQLRQE-----MGKEEEENESFGLSREYEELIKLKRSGSIQAKNLKSKFE---KIGQLSEKEVQKKIEEERAKRRA 393
Cdd:PTZ00121 1646 KKKAEELKKAeeenkIKAAEEAKKAEEDKKKAEEAKKAEEDEKKAAEALKKEAEeakKAEELKKKEAEEKKKAEELKKAE 1725

                         410       420
                  ....*....|....*....|....*...
gi 755504364  394 IDLEIKEREAENFHEDDDVDVRPAKKSE 421
Cdd:PTZ00121 1726 EENKIKAEEAKKEAEEDKKKAEEAKKDE 1753

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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364 499 PWFKKPLRNTSVVDSEPVRFTVKVTGEPKPEITWWFEGEILQ---DGEDYQYIERGETYCLYLPETFPEDGGEYMCKAVN 575
Cdd:cd20951    1 PEFIIRLQSHTVWEKSDAKLRVEVQGKPDPEVKWYKNGVPIDpssIPGKYKIESEYGVHVLHIRRVTVEDSAVYSAVAKN 80

                         90
                 ....*....|....
gi 755504364 576 NKGSAASTCILTIE 589
Cdd:cd20951   81 IHGEASSSASVVVE 94

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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364 503 KPLRNTSVVDSEPVRFTVKVTGEPKPEITWWFEGEILQDGEDYQYIERGETYC-LYLPETFPEDGGEYMCKAVNNKGSAA 581
Cdd:cd20973    2 QTLRDKEVVEGSAARFDCKVEGYPDPEVKWMKDDNPIVESRRFQIDQDEDGLCsLIISDVCGDDSGKYTCKAVNSLGEAT 81

                 ....*..
gi 755504364 582 STCILTI 588
Cdd:cd20973   82 CSAELTV 88

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.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 755504364 500 WFKKPLRNTSVVDSEPVRFTVKVTGEPKPEITWWFEGEILQDGEDYQYIERGEtycLYLPETFPEDGGEYMCKAVNNKG 578
Cdd:cd20978    3 FIQKPEKNVVVKGGQDVTLPCQVTGVPQPKITWLHNGKPLQGPMERATVEDGT---LTIINVQPEDTGYYGCVATNEIG 78

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

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364   506 RNTSVVDSEPVRFTVKVTGEPKPEITWWFEG-EILQDGEDYQYIERGETYCLYLPETFPEDGGEYMCKAVNNKGSAASTC 584
Cdd:smart00410   2 PSVTVKEGESVTLSCEASGSPPPEVTWYKQGgKLLAESGRFSVSRSGSTSTLTISNVTPEDSGTYTCAATNSSGSASSGT 81

                   ....
gi 755504364   585 ILTI 588
Cdd:smart00410  82 TLTV 85

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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364 504 PLRNTSVVDSEPVRFTVKVTGEPKPEITWWFEGEILQDG-EDYQYIERGETycLYLPETFPEDGGEYMCKAVNNKGSAAS 582
Cdd:cd20970    8 PSFTVTAREGENATFMCRAEGSPEPEISWTRNGNLIIEFnTRYIVRENGTT--LTIRNIRRSDMGIYLCIASNGVPGSVE 85

                 ...
gi 755504364 583 TCI 585
Cdd:cd20970   86 KRI 88

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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364 498 APWFKKPLRNTSVVDSEPVRFTVKVTGEPKPEITWWFEGEILQDGEDYQYIERGeTYCLYLPETFPEDGGEYMCKAVNNK 577
Cdd:cd20976    1 APSFSSVPKDLEAVEGQDFVAQCSARGKPVPRITWIRNAQPLQYAADRSTCEAG-VGELHIQDVLPEDHGTYTCLAKNAA 79

                         90
                 ....*....|.
gi 755504364 578 GSAASTCILTI 588
Cdd:cd20976   80 GQVSCSAWVTV 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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364 498 APWFKKPLRNTSVVDSEPVRFTVKVTGEPKPEITWWFEGEILQDGEDYQYIER--GETYCLYLPETFPEDGGEYMCKAVN 575
Cdd:cd20971    1 APHFKEELRNLNVRYQSNATLVCKVTGHPKPIVKWYRQGKEIIADGLKYRIQEfkGGYHQLIIASVTDDDATVYQVRATN 80

                 ....*..
gi 755504364 576 NKGSAAS 582
Cdd:cd20971   81 QGGSVSG 87

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.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364  503 KPLRNTSVVDSEPVRFTVKV-TGEPKPEITWWFEGEILQDGEDYQYIERGET-YCLYLPETFPEDGGEYMCKAVNNKGSA 580
Cdd:pfam00047   1 SAPPTVTVLEGDSATLTCSAsTGSPGPDVTWSKEGGTLIESLKVKHDNGRTTqSSLLISNVTKEDAGTYTCVVNNPGGSA 80

                  ...
gi 755504364  581 AST 583
Cdd:pfam00047  81 TLS 83

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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364 499 PWFKK-PLRNTS-VVDSEPVRFTVKVTGEPKPEITWWFEGEILQDGEDYQYIERGEtycLYLPETFPEDGGEYMCKAVNN 576
Cdd:cd04969    1 PDFELnPVKKKIlAAKGGDVIIECKPKASPKPTISWSKGTELLTNSSRICILPDGS---LKIKNVTKSDEGKYTCFAVNF 77

                         90
                 ....*....|..
gi 755504364 577 KGSAASTCILTI 588
Cdd:cd04969   78 FGKANSTGSLSV 89

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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364 503 KPlRNTSVVDSEPVRFTVKVTGEPKPEITWWFEGEILQDGEDYQYIERGETYCLYLPETFPEDGGEYMCKAVNNKGSAAS 582
Cdd:cd05747    9 KP-RSLTVSEGESARFSCDVDGEPAPTVTWMREGQIIVSSQRHQITSTEYKSTFEISKVQMSDEGNYTVVVENSEGKQEA 87

                 ....*
gi 755504364 583 TCILT 587
Cdd:cd05747   88 QFTLT 92

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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364 507 NTSVVDSEPVRFTVKVTGEPKPEITWWFEGEI-----LQDGEDYQYIERG--------ETYCLYLPETFPEDGGEYMCKA 573
Cdd:cd05858   10 NTSVVVGTDAEFVCKVYSDAQPHIQWLKHVEKngskyGPDGLPYVEVLKTagvnttdkEIEVLYLRNVTFEDAGEYTCLA 89

                         90
                 ....*....|....*
gi 755504364 574 VNNKGSAASTCILTI 588
Cdd:cd05858   90 GNSIGISHHSAWLTV 104

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.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364 498 APWFKKPLRNTSVVDSEpVRFTVKVTGEPKPEITWWFEG----EI---LQDGEDYQYIERGETY------CLYLPETFPE 564
Cdd:cd20940    1 AGFIKSPLSQQRLVGDS-VELHCEAVGSPIPEIQWWFEGqepnEIcsqLWDGARLDRVHINATYhqhatsTISIDNLTEE 79

                         90
                 ....*....|..
gi 755504364 565 DGGEYMCKAVNN 576
Cdd:cd20940   80 DTGTYECRASND 91

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.

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364 503 KPLRNTSVVDSEPVRFTVKVTGEPKPEITWWFEGEILQDGEDYQYIERGetycLYLPETFPEDGGEYMCKAVNNKGSAAS 582
Cdd:cd05725    2 KRPQNQVVLVDDSAEFQCEVGGDPVPTVRWRKEDGELPKGRYEILDDHS----LKIRKVTAGDMGSYTCVAENMVGKIEA 77

                 ....*.
gi 755504364 583 TCILTI 588
Cdd:cd05725   78 SATLTV 83

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.

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....
gi 755504364 523 TGEPKPEITWWFEGEILQDGEDYQY----IERGET--YcLYLPETFPEDGGEYMCKAVNNKGSA 580
Cdd:cd20956   26 SGNPLPQITWTLDGFPIPESPRFRVgdyvTSDGDVvsY-VNISSVRVEDGGEYTCTATNDVGSV 88

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.

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364 502 KKPLRNTSVVDSEPVRFTVKVTGEPKPEITWWFEGEILQDGEDYQYIERGETyCLYLPETFPEDGGEYMCKAVNNKGSAA 581
Cdd:cd05760    5 KHPASAAEIQPSSRVTLRCHIDGHPRPTYQWFRDGTPLSDGQGNYSVSSKER-TLTLRSAGPDDSGLYYCCAHNAFGSVC 83

                         90
                 ....*....|.
gi 755504364 582 STCILTIEMDD 592
Cdd:cd05760   84 SSQNFTLSIID 94

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.

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gi 755504364 507 NTSVVDSEPVRFTVKVTGePKPEITWWFEGEILQDGEDYQYIERGETycLYLPETFPEDGGEYMCKAVN 575
Cdd:cd05740    9 SNPVEDKDAVTLTCEPET-QNTSYLWWFNGQSLPVTPRLTLSNGNRT--LTLLNVTREDAGAYQCEISN 74

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.

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gi 755504364 524 GEPKPEITWW-FEGEILQDGEDYQYIERgetyCLYLPETFPEDGGEYMCKAVNNKGSAASTCILTIE 589
Cdd:cd05876   21 GLPTPTVKWLrPSGPLPPDRVKYQNHNK----TLQLLNVGESDDGEYVCLAENSLGSARHAYYVTVE 83

Third immunoglobulin-like domain of the human WFIKKN (WAP, follistatin, immunoglobulin, Kunitz and NTR domain-containing protein), and similar domains; member of the I-set of Ig superfamily (IgSF) domains; The members here are composed of the third immunoglobulin-like domain of the human WFIKKN (WAP, follistatin, immunoglobulin, Kunitz and NTR domain-containing protein) and similar proteins. WFIKKN is a secreted protein that consists of multiple types of protease inhibitory modules, including two tandem Kunitz-type protease inhibitor-domains. The Ig superfamily is a heterogenous group of proteins built on a common fold comprised of a sandwich of two beta sheets. Members of the Ig superfamily 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. 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.

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gi 755504364 509 SVVDSEPVRFTVKVTGEPKPEITW--WFEGE---ILQDGEDYQYIERGETYCLYLPETFPEDGGEYMCKAVNNKGS 579
Cdd:cd05765   11 TVKVGETASFHCDVTGRPQPEITWekQVPGKenlIMRPNHVRGNVVVTNIGQLVIYNAQPQDAGLYTCTARNSGGL 86

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.

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gi 755504364 524 GEPKPEITWWFEG-EILQDGEDYQYIERGEtycLYLPETFPEDGGEYMCKAVNNKGSAAS 582
Cdd:cd05724   24 GHPEPTVSWRKDGqPLNLDNERVRIVDDGN---LLIAEARKSDEGTYKCVATNMVGERES 80

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.

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gi 755504364 500 WFKKPlRNTSVVDSEPVRFTVKVTGEPKPEITWWFEGEILQD-GEDYQYIERGETycLYLPETFPEDGGEYMCKAVNNKG 578
Cdd:cd04978    2 WIIEP-PSLVLSPGETGELICEAEGNPQPTITWRLNGVPIEPaPEDMRRTVDGRT--LIFSNLQPNDTAVYQCNASNVHG 78

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.

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364 502 KKPLrNTSVVDSEPVRFTVKVTGEPKPEITWWFEGEILQDGEDYQYIERGETYCLYLPETfpeDGGEYMCKAVNNKGSAA 581
Cdd:cd05723    2 KKPS-NIYAHESMDIVFECEVTGKPTPTVKWVKNGDVVIPSDYFKIVKEHNLQVLGLVKS---DEGFYQCIAENDVGNAQ 77

                 ....*..
gi 755504364 582 STCILTI 588
Cdd:cd05723   78 ASAQLII 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.

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                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 755504364 502 KKPLRNTSVVDSEPVRFTVKVTGEPKPEITWWFEGEILQDGEDYQYIERGEtycLYLPETFPEDGGEYMCKAVNNKGSAA 581
Cdd:cd20968    3 TRPPTNVTIIEGLKAVLPCTTMGNPKPSVSWIKGDDLIKENNRIAVLESGS---LRIHNVQKEDAGQYRCVAKNSLGIAY 79

                 .
gi 755504364 582 S 582
Cdd:cd20968   80 S 80

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.

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gi 755504364 505 LRNTSVVDSEPVRFTVKVTGEPKPEITWWFEGEILQDGE---DYQYIERGE--TYCLYLPETFPEDGGEYMCKAVNNKG 578
Cdd:cd05732    8 LENQTAVELEQITLTCEAEGDPIPEITWRRATRGISFEEgdlDGRIVVRGHarVSSLTLKDVQLTDAGRYDCEASNRIG 86