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Conserved domains on  [gi|568922100|ref|XP_006501210|]
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prostaglandin F2 receptor negative regulator isoform X2 [Mus musculus]

Protein Classification

immunoglobulin domain-containing protein( domain architecture ID 10647953)

immunoglobulin (Ig) domain-containing protein adopts a fold comprised of a sandwich of two beta sheets and may function in cell adhesion and pattern recognition

Graphical summary

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List of domain hits

Name Accession Description Interval E-value
Ig super family cl11960
Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found ...
271-361 1.02e-05

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.


The actual alignment was detected with superfamily member pfam07679:

Pssm-ID: 472250 [Multi-domain]  Cd Length: 90  Bit Score: 44.56  E-value: 1.02e-05
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568922100  271 VPRTVSVTEGKDLDLSCNITTDRVddvrPEVTWYFKktpdtsllashmlarldrDSLVHSSPHVALSHVDTRsYHLLVRD 350
Cdd:pfam07679   6 KPKDVEVQEGESARFTCTVTGTPD----PEVSWFKD------------------GQPLRSSDRFKVTYEGGT-YTLTISN 62
                          90
                  ....*....|.
gi 568922100  351 VSKENSGYYLC 361
Cdd:pfam07679  63 VQPDDSGKYTC 73
Ig super family cl11960
Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found ...
141-242 1.68e-05

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.


The actual alignment was detected with superfamily member cd00099:

Pssm-ID: 472250 [Multi-domain]  Cd Length: 111  Bit Score: 44.63  E-value: 1.68e-05
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568922100 141 PPPGLSLREGEPFELRCIASTTsplHTHLALRWELHRGPVHRSILALSHEGRFHPGPGYEQRYHSgdvrlDTVGSDAYRL 220
Cdd:cd00099    4 SPRSLSVQEGESVTLSCEVSSS---FSSTYIYWYRQKPGQGPEFLIYLSSSKGKTKGGVPGRFSG-----SRDGTSSFSL 75
                         90       100
                 ....*....|....*....|..
gi 568922100 221 SVARALSADQGSYRCVVSEWIT 242
Cdd:cd00099   76 TISNLQPEDSGTYYCAVSESGG 97
IGv smart00406
Immunoglobulin V-Type;
27-109 1.39e-04

Immunoglobulin V-Type;


:

Pssm-ID: 214650  Cd Length: 81  Bit Score: 41.21  E-value: 1.39e-04
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568922100    27 LVIPCNVSDYDgPSEQNFDWSFSSSGSSfVELASTWE---VGFPAQLYRERLQrgdiLLRRTANDAVELHIKNVQPSDQG 103
Cdd:smart00406   2 VTLSCKFSGST-FSSYYVSWVRQPPGKG-LEWLGYIGsngSSYYQESYKGRFT----ISKDTSKNDVSLTISNLRVEDTG 75

                   ....*.
gi 568922100   104 HYKCST 109
Cdd:smart00406  76 TYYCAV 81
Ig super family cl11960
Immunoglobulin domain; The members here are composed of the immunoglobulin (Ig) domain found ...
92-128 4.30e-03

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.


The actual alignment was detected with superfamily member cd16091:

Pssm-ID: 472250  Cd Length: 107  Bit Score: 37.75  E-value: 4.30e-03
                         10        20        30
                 ....*....|....*....|....*....|....*..
gi 568922100  92 LHIKNVQPSDQGHYKCSTpstdATVQGNYEDTVQVKV 128
Cdd:cd16091   75 LLLRRVQLQDEGRYKCYT----STIIGNQESFVNLKV 107
 
Name Accession Description Interval E-value
I-set pfam07679
Immunoglobulin I-set domain;
271-361 1.02e-05

Immunoglobulin I-set domain;


Pssm-ID: 400151 [Multi-domain]  Cd Length: 90  Bit Score: 44.56  E-value: 1.02e-05
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568922100  271 VPRTVSVTEGKDLDLSCNITTDRVddvrPEVTWYFKktpdtsllashmlarldrDSLVHSSPHVALSHVDTRsYHLLVRD 350
Cdd:pfam07679   6 KPKDVEVQEGESARFTCTVTGTPD----PEVSWFKD------------------GQPLRSSDRFKVTYEGGT-YTLTISN 62
                          90
                  ....*....|.
gi 568922100  351 VSKENSGYYLC 361
Cdd:pfam07679  63 VQPDDSGKYTC 73
IG_like smart00410
Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.
272-363 1.47e-05

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: 44.03  E-value: 1.47e-05
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568922100   272 PRTVSVTEGKDLDLSCNITTDRVddvrPEVTWYFkktpdtsllashmlarlDRDSLVHSSPHVALSHvDTRSYHLLVRDV 351
Cdd:smart00410   1 PPSVTVKEGESVTLSCEASGSPP----PEVTWYK-----------------QGGKLLAESGRFSVSR-SGSTSTLTISNV 58
                           90
                   ....*....|..
gi 568922100   352 SKENSGYYLCLV 363
Cdd:smart00410  59 TPEDSGTYTCAA 70
IgV cd00099
Immunoglobulin variable domain (IgV); The members here are composed of the immunoglobulin ...
141-242 1.68e-05

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: 44.63  E-value: 1.68e-05
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568922100 141 PPPGLSLREGEPFELRCIASTTsplHTHLALRWELHRGPVHRSILALSHEGRFHPGPGYEQRYHSgdvrlDTVGSDAYRL 220
Cdd:cd00099    4 SPRSLSVQEGESVTLSCEVSSS---FSSTYIYWYRQKPGQGPEFLIYLSSSKGKTKGGVPGRFSG-----SRDGTSSFSL 75
                         90       100
                 ....*....|....*....|..
gi 568922100 221 SVARALSADQGSYRCVVSEWIT 242
Cdd:cd00099   76 TISNLQPEDSGTYYCAVSESGG 97
IGv smart00406
Immunoglobulin V-Type;
27-109 1.39e-04

Immunoglobulin V-Type;


Pssm-ID: 214650  Cd Length: 81  Bit Score: 41.21  E-value: 1.39e-04
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568922100    27 LVIPCNVSDYDgPSEQNFDWSFSSSGSSfVELASTWE---VGFPAQLYRERLQrgdiLLRRTANDAVELHIKNVQPSDQG 103
Cdd:smart00406   2 VTLSCKFSGST-FSSYYVSWVRQPPGKG-LEWLGYIGsngSSYYQESYKGRFT----ISKDTSKNDVSLTISNLRVEDTG 75

                   ....*.
gi 568922100   104 HYKCST 109
Cdd:smart00406  76 TYYCAV 81
CD19_protodomain_1_2 cd23999
CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold protodomain 1 ...
273-369 2.11e-04

CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold protodomain 1 and 2; CD19, also known as B-Lymphocyte Surface Antigen B4, T-Cell Surface Antigen Leu-12, and CVID3, is a transmembrane receptor present on various types of B cells, including progenitor, naive, and memory B cells, as well as plasmablasts. Until recently, it was believed to comprise two extracellular immunoglobulin (Ig) structural domains arranged in tandem with C2 topology. However, recent crystal structures have shown that the CD19 extracellular domain contains a unique double Ig domain that is responsible for its binding to proteins such as CD21, CD81, and CD225, which regulate B cell activation and survival. A recent analysis of the CD19 extracellular domain sequence reveals two "Ig domains", but the structure demonstrates that these two domains are not folded independently and connected in tandem. Rather, they fold together as one intertwined domain that can be referred to as a "double Ig" domain. Each of the two regular Ig domain sequences has a noticeably short linker that forms a loop between strands C' and D, rather than allowing the formation of a C" strand. Additionally, the two Ig-domain sequences are separated by a long linker that is structured as a small insertion domain, enabling both Ig sequences to fold together as a unique double Ig-domain. The CD19 domain comprises four "protodomains": two formed by A'B-CC' strands and two by DE-FG strands that interdigitate to form a novel double Ig fold. When analyzing this double Ig domain in terms of the usual Ig-fold, A'B-CC' protodomain of the first Ig sequence combines with DE-FG protodomain of the second, and vice versa. Hence, the second combined Ig fold is inverted, with DE-FG protodomain of the first Ig sequence combining with A'B-CC' protodomain of the second Ig sequence and in that order, as if it were a circular permutation, obtained only through structural folding. This group contains the protodomains 1 and 2 of the CD19 double Ig domain.


Pssm-ID: 467826  Cd Length: 92  Bit Score: 40.87  E-value: 2.11e-04
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568922100 273 RTVSVTEGKDLDLSCNIttDRVDDVRPEVTWYfKKTPDTSLLAshmlarldrdsLVHSSPHVALsHVDTRSYHLLVRDVS 352
Cdd:cd23999    1 LLVEVEEGDNAVLPCLI--GPSDGPPEQLTWS-RGGQLEPFLQ-----------LSLGSPGLGA-QVGPLGIWLFIFNVS 65
                         90       100
                 ....*....|....*....|..
gi 568922100 353 KENSGYYLCLVAL-----WAPG 369
Cdd:cd23999   66 EQMGGFYLCELGPpskqaWQPG 87
IgV_HHLA2 cd16091
Immunoglobulin Variable (IgV) domain in HERV-H LTR-associating 2 (HHLA2); The members here are ...
92-128 4.30e-03

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: 37.75  E-value: 4.30e-03
                         10        20        30
                 ....*....|....*....|....*....|....*..
gi 568922100  92 LHIKNVQPSDQGHYKCSTpstdATVQGNYEDTVQVKV 128
Cdd:cd16091   75 LLLRRVQLQDEGRYKCYT----STIIGNQESFVNLKV 107
IgV_MOG_like cd05713
Immunoglobulin (Ig)-like domain of myelin oligodendrocyte glycoprotein (MOG); The members here ...
71-107 6.50e-03

Immunoglobulin (Ig)-like domain of myelin oligodendrocyte glycoprotein (MOG); The members here are composed of the immunoglobulin (Ig)-like domain of myelin oligodendrocyte glycoprotein (MOG). MOG, a minor component of the myelin sheath, is an important CNS-specific autoantigen, linked to the pathogenesis of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE). It is a transmembrane protein having an extracellular Ig domain. MOG is expressed in the CNS on the outermost lamellae of the myelin sheath, and on the surface of oligodendrocytes, and may participate in the completion, compaction, and/or maintenance of myelin. This group also includes butyrophilin (BTN). BTN is the most abundant protein in bovine milk-fat globule membrane (MFGM).


Pssm-ID: 409378  Cd Length: 114  Bit Score: 37.17  E-value: 6.50e-03
                         10        20        30
                 ....*....|....*....|....*....|....*....
gi 568922100  71 YRER--LQRGDIllrrtANDAVELHIKNVQPSDQGHYKC 107
Cdd:cd05713   63 YRGRteLLKDAI-----AEGSVALRIHNVRPSDEGQYTC 96
 
Name Accession Description Interval E-value
I-set pfam07679
Immunoglobulin I-set domain;
271-361 1.02e-05

Immunoglobulin I-set domain;


Pssm-ID: 400151 [Multi-domain]  Cd Length: 90  Bit Score: 44.56  E-value: 1.02e-05
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568922100  271 VPRTVSVTEGKDLDLSCNITTDRVddvrPEVTWYFKktpdtsllashmlarldrDSLVHSSPHVALSHVDTRsYHLLVRD 350
Cdd:pfam07679   6 KPKDVEVQEGESARFTCTVTGTPD----PEVSWFKD------------------GQPLRSSDRFKVTYEGGT-YTLTISN 62
                          90
                  ....*....|.
gi 568922100  351 VSKENSGYYLC 361
Cdd:pfam07679  63 VQPDDSGKYTC 73
IG_like smart00410
Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.
272-363 1.47e-05

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: 44.03  E-value: 1.47e-05
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568922100   272 PRTVSVTEGKDLDLSCNITTDRVddvrPEVTWYFkktpdtsllashmlarlDRDSLVHSSPHVALSHvDTRSYHLLVRDV 351
Cdd:smart00410   1 PPSVTVKEGESVTLSCEASGSPP----PEVTWYK-----------------QGGKLLAESGRFSVSR-SGSTSTLTISNV 58
                           90
                   ....*....|..
gi 568922100   352 SKENSGYYLCLV 363
Cdd:smart00410  59 TPEDSGTYTCAA 70
IgV cd00099
Immunoglobulin variable domain (IgV); The members here are composed of the immunoglobulin ...
141-242 1.68e-05

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: 44.63  E-value: 1.68e-05
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568922100 141 PPPGLSLREGEPFELRCIASTTsplHTHLALRWELHRGPVHRSILALSHEGRFHPGPGYEQRYHSgdvrlDTVGSDAYRL 220
Cdd:cd00099    4 SPRSLSVQEGESVTLSCEVSSS---FSSTYIYWYRQKPGQGPEFLIYLSSSKGKTKGGVPGRFSG-----SRDGTSSFSL 75
                         90       100
                 ....*....|....*....|..
gi 568922100 221 SVARALSADQGSYRCVVSEWIT 242
Cdd:cd00099   76 TISNLQPEDSGTYYCAVSESGG 97
V-set pfam07686
Immunoglobulin V-set domain; This domain is found in antibodies as well as neural protein P0 ...
271-364 3.47e-05

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: 43.60  E-value: 3.47e-05
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568922100  271 VPRTVSVTEGKDLDLSCNITTDRVDDVrPEVTWYFKKTPDTSllaSHMLARLDRDS--LVHSSPHVALSHVDTRSYHLLV 348
Cdd:pfam07686   2 TPREVTVALGGSVTLPCTYSSSMSEAS-TSVYWYRQPPGKGP---TFLIAYYSNGSeeGVKKGRFSGRGDPSNGDGSLTI 77
                          90
                  ....*....|....*.
gi 568922100  349 RDVSKENSGYYLCLVA 364
Cdd:pfam07686  78 QNLTLSDSGTYTCAVI 93
IGv smart00406
Immunoglobulin V-Type;
27-109 1.39e-04

Immunoglobulin V-Type;


Pssm-ID: 214650  Cd Length: 81  Bit Score: 41.21  E-value: 1.39e-04
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568922100    27 LVIPCNVSDYDgPSEQNFDWSFSSSGSSfVELASTWE---VGFPAQLYRERLQrgdiLLRRTANDAVELHIKNVQPSDQG 103
Cdd:smart00406   2 VTLSCKFSGST-FSSYYVSWVRQPPGKG-LEWLGYIGsngSSYYQESYKGRFT----ISKDTSKNDVSLTISNLRVEDTG 75

                   ....*.
gi 568922100   104 HYKCST 109
Cdd:smart00406  76 TYYCAV 81
CD19_protodomain_1_2 cd23999
CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold protodomain 1 ...
273-369 2.11e-04

CD19 (Cluster of Differentiation 19), a unique double immunoglobulin (Ig)-fold protodomain 1 and 2; CD19, also known as B-Lymphocyte Surface Antigen B4, T-Cell Surface Antigen Leu-12, and CVID3, is a transmembrane receptor present on various types of B cells, including progenitor, naive, and memory B cells, as well as plasmablasts. Until recently, it was believed to comprise two extracellular immunoglobulin (Ig) structural domains arranged in tandem with C2 topology. However, recent crystal structures have shown that the CD19 extracellular domain contains a unique double Ig domain that is responsible for its binding to proteins such as CD21, CD81, and CD225, which regulate B cell activation and survival. A recent analysis of the CD19 extracellular domain sequence reveals two "Ig domains", but the structure demonstrates that these two domains are not folded independently and connected in tandem. Rather, they fold together as one intertwined domain that can be referred to as a "double Ig" domain. Each of the two regular Ig domain sequences has a noticeably short linker that forms a loop between strands C' and D, rather than allowing the formation of a C" strand. Additionally, the two Ig-domain sequences are separated by a long linker that is structured as a small insertion domain, enabling both Ig sequences to fold together as a unique double Ig-domain. The CD19 domain comprises four "protodomains": two formed by A'B-CC' strands and two by DE-FG strands that interdigitate to form a novel double Ig fold. When analyzing this double Ig domain in terms of the usual Ig-fold, A'B-CC' protodomain of the first Ig sequence combines with DE-FG protodomain of the second, and vice versa. Hence, the second combined Ig fold is inverted, with DE-FG protodomain of the first Ig sequence combining with A'B-CC' protodomain of the second Ig sequence and in that order, as if it were a circular permutation, obtained only through structural folding. This group contains the protodomains 1 and 2 of the CD19 double Ig domain.


Pssm-ID: 467826  Cd Length: 92  Bit Score: 40.87  E-value: 2.11e-04
                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568922100 273 RTVSVTEGKDLDLSCNIttDRVDDVRPEVTWYfKKTPDTSLLAshmlarldrdsLVHSSPHVALsHVDTRSYHLLVRDVS 352
Cdd:cd23999    1 LLVEVEEGDNAVLPCLI--GPSDGPPEQLTWS-RGGQLEPFLQ-----------LSLGSPGLGA-QVGPLGIWLFIFNVS 65
                         90       100
                 ....*....|....*....|..
gi 568922100 353 KENSGYYLCLVAL-----WAPG 369
Cdd:cd23999   66 EQMGGFYLCELGPpskqaWQPG 87
Ig_3 pfam13927
Immunoglobulin domain; This family contains immunoglobulin-like domains.
272-363 4.03e-04

Immunoglobulin domain; This family contains immunoglobulin-like domains.


Pssm-ID: 464046 [Multi-domain]  Cd Length: 78  Bit Score: 39.86  E-value: 4.03e-04
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568922100  272 PRTVSVTEGKDLDLSCNITTDRvddvRPEVTWYfkktpdtsllashmlarldRDSLVHSSPHVALSHVDTRSYHLLVRDV 351
Cdd:pfam13927   8 PSSVTVREGETVTLTCEATGSP----PPTITWY-------------------KNGEPISSGSTRSRSLSGSNSTLTISNV 64
                          90
                  ....*....|..
gi 568922100  352 SKENSGYYLCLV 363
Cdd:pfam13927  65 TRSDAGTYTCVA 76
ig pfam00047
Immunoglobulin domain; Members of the immunoglobulin superfamily are found in hundreds of ...
271-363 3.98e-03

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: 3.98e-03
                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568922100  271 VPRTVSVTEGKDLDLSCNITTDRVDdvrPEVTWYFKKTpdtsllashmlarldrdSLVHSSPHValsHVDTRSYH--LLV 348
Cdd:pfam00047   2 APPTVTVLEGDSATLTCSASTGSPG---PDVTWSKEGG-----------------TLIESLKVK---HDNGRTTQssLLI 58
                          90
                  ....*....|....*
gi 568922100  349 RDVSKENSGYYLCLV 363
Cdd:pfam00047  59 SNVTKEDAGTYTCVV 73
IgV_HHLA2 cd16091
Immunoglobulin Variable (IgV) domain in HERV-H LTR-associating 2 (HHLA2); The members here are ...
92-128 4.30e-03

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: 37.75  E-value: 4.30e-03
                         10        20        30
                 ....*....|....*....|....*....|....*..
gi 568922100  92 LHIKNVQPSDQGHYKCSTpstdATVQGNYEDTVQVKV 128
Cdd:cd16091   75 LLLRRVQLQDEGRYKCYT----STIIGNQESFVNLKV 107
IG_like smart00410
Immunoglobulin like; IG domains that cannot be classified into one of IGv1, IGc1, IGc2, IG.
17-128 4.74e-03

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: 37.10  E-value: 4.74e-03
                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 568922100    17 GTLVRVVGTELVIPCNVSdydGPSEQNFDWsfsssgssfvelastwevgfpaqlYRERLQ----RGDILLRRTANDAVeL 92
Cdd:smart00410   2 PSVTVKEGESVTLSCEAS---GSPPPEVTW------------------------YKQGGKllaeSGRFSVSRSGSTST-L 53
                           90       100       110
                   ....*....|....*....|....*....|....*.
gi 568922100    93 HIKNVQPSDQGHYKCSTPSTdatvQGNYEDTVQVKV 128
Cdd:smart00410  54 TISNVTPEDSGTYTCAATNS----SGSASSGTTLTV 85
IgV_MOG_like cd05713
Immunoglobulin (Ig)-like domain of myelin oligodendrocyte glycoprotein (MOG); The members here ...
71-107 6.50e-03

Immunoglobulin (Ig)-like domain of myelin oligodendrocyte glycoprotein (MOG); The members here are composed of the immunoglobulin (Ig)-like domain of myelin oligodendrocyte glycoprotein (MOG). MOG, a minor component of the myelin sheath, is an important CNS-specific autoantigen, linked to the pathogenesis of multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE). It is a transmembrane protein having an extracellular Ig domain. MOG is expressed in the CNS on the outermost lamellae of the myelin sheath, and on the surface of oligodendrocytes, and may participate in the completion, compaction, and/or maintenance of myelin. This group also includes butyrophilin (BTN). BTN is the most abundant protein in bovine milk-fat globule membrane (MFGM).


Pssm-ID: 409378  Cd Length: 114  Bit Score: 37.17  E-value: 6.50e-03
                         10        20        30
                 ....*....|....*....|....*....|....*....
gi 568922100  71 YRER--LQRGDIllrrtANDAVELHIKNVQPSDQGHYKC 107
Cdd:cd05713   63 YRGRteLLKDAI-----AEGSVALRIHNVRPSDEGQYTC 96
 
Blast search parameters
Data Source: Precalculated data, version = cdd.v.3.21
Preset Options:Database: CDSEARCH/cdd   Low complexity filter: no  Composition Based Adjustment: yes   E-value threshold: 0.01

References:

  • Wang J et al. (2023), "The conserved domain database in 2023", Nucleic Acids Res.51(D)384-8.
  • Lu S et al. (2020), "The conserved domain database in 2020", Nucleic Acids Res.48(D)265-8.
  • Marchler-Bauer A et al. (2017), "CDD/SPARCLE: functional classification of proteins via subfamily domain architectures.", Nucleic Acids Res.45(D)200-3.
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