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.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 90903245 184 TC-SATARPAPMVFWKVPRSGIENSTvTLSHPNGTTSVTSILHIKDPKNQVGKEVICQVLHLGTVTDFKQTVN 255
Cdd:cd05719  22 TCiSANGKPPASVTWETDLKGEASTT-QVRGSNGTVTVTSRYRLVPSREADGQPLTCVVEHPSLEKDQRISVT 93

Immunoglobulin V-Type;

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90903245     72 ASLKCSL-QNAQEALIVTWQKKK-AVSPENMVTFSENHGVVIQPAYKDKINITQLGLQNS-TITFWNITLEDEGCYMCLF 148
Cdd:smart00406   2 VTLSCKFsGSTFSSYYVSWVRQPpGKGLEWLGYIGSNGSSYYQESYKGRFTISKDTSKNDvSLTISNLRVEDTGTYYCAV 81

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 90903245    72 ASLKCSLQNAQEALIVTWQKKKAVSPENMvtfsenhgvviqpaykdKINITQLGLQNSTITFWNITLEDEGCYMCLFNTF 151
Cdd:pfam00047  14 ATLTCSASTGSPGPDVTWSKEGGTLIESL-----------------KVKHDNGRTTQSSLLISNVTKEDAGTYTCVVNNP 76

                          90
                  ....*....|
gi 90903245   152 GFGKISGTAC 161
Cdd:pfam00047  77 GGSATLSTSL 86

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
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 90903245   168 PIVSLHYKFSEDHLNITCSA-TARPAPMVFWKVPRSGIENSTVTlSHPNGTTSVTSILHIKDPKNQVGkEVICQVLHLG 245
Cdd:pfam00047   1 SAPPTVTVLEGDSATLTCSAsTGSPGPDVTWSKEGGTLIESLKV-KHDNGRTTQSSLLISNVTKEDAG-TYTCVVNNPG 77

First immunoglobulin variable (IgV) domain of poliovirus receptor (PVR, also known as CD155 and necl-5), and similar domains; The members here are composed of the first immunoglobulin (Ig) domain of poliovirus receptor (PVR, also known as CD155 and nectin-like protein 5 (necl-5)). Poliovirus (PV) binds to its cellular receptor (PVR/CD155) to initiate infection. CD155 is a membrane-anchored, single-span glycoprotein; its extracellular region has three Ig-like domains. There are four different isotypes of CD155 (referred to as alpha, beta, gamma, and delta), that result from alternate splicing of the CD155 mRNA, and have identical extracellular domains. CD155-beta and CD155-gamma are secreted; CD155-alpha and CD155-delta are membrane-bound and function as PV receptors. The virus recognition site is contained in the amino-terminal domain, D1. Having the virus attachment site on the receptor distal from the plasma membrane may be important for successful initiation of infection of cells by the virus. CD155 binds in the poliovirus "canyon" with a footprint similar to that of the intercellular adhesion molecule-1 receptor on human rhinoviruses. This group also includes the first Ig-like domain of nectin-1 (also known as poliovirus receptor related protein(PVRL)1; CD111), nectin-3 (also known as PVRL 3), nectin-4 (also known as PVRL4; LNIR receptor)and DNAX accessory molecule 1 (DNAM-1; CD226).

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90903245  56 QVQVVTQdEREQLYTPASLKCSLQNAQEALI--VTWQKKKAVSPENMVTFSENHGVVIQPAYKDKINIT--QLGLQNSTI 131
Cdd:cd05718   2 RVQVPTE-VTGFLGGSVTLPCSLTSPGTTKItqVTWMKIGAGSSQNVAVFHPQYGPSVPNPYAERVEFLaaRLGLRNATL 80

                        90       100       110
                ....*....|....*....|....*....|...
gi 90903245 132 TFWNITLEDEGCYMCLFNTFGFGKISGTACLTV 164
Cdd:cd05718  81 RIRNLRVEDEGNYICEFATFPQGNRQGTTWLRV 113

First immunoglobulin variable (IgV) domain of nectin-2, nectin-like protein 5, and similar domains; The members here are composed of the second immunoglobulin (Ig) domain of nectin-2 (also known as poliovirus receptor related protein 2 or Cluster of Differentiation 112 (CD112)), nectin-like protein 5 (CD155), and similar proteins. Nectins and Nectin-like molecules are a family of Ca(2+)-independent immunoglobulin-like transmembrane glycoproteins belonging to the class of adhesion receptors, consisting of nine members (nectins 1 through 4 and nectin-like proteins 1 through 5). Nectins are synaptic cell adhesion molecules (CAMs) which facilitate adhesion and signaling at various intracellular junctions. Nectins form homophilic cis-dimers, followed by homophilic and heterophilic trans-dimers involved in cell-cell adhesion. Nectin-2 and nectin-3 localize at Sertoli-spermatid junctions where they form heterophilic trans-interactions between the cells that are essential for the formation and maintenance of the junctions and for spermatid development. CD155 is the fifth member in the nectin-like molecule family, and functions as the receptor of poliovirus; therefore, CD155 is also referred to as Necl-5, or PVR. In contrast to all other family members, CD155 lacks self-adhesion capacity, yet it shares with nectins the feature to interact with other nectins. For instance, CD155 heterophilically trans-interacts with nectin-3, thereby contributing significantly to the establishment of adherens junctions between epithelial cells. This group belongs to the Constant 1 (C1)-set of IgSF domains, which has one beta-sheet that is formed by strands A-B-E-D and the other strands by G-F-C-C'.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90903245  57 VQVVTQdEREQLYTPASLKCSLQ---NAQEALIVTWQKKKavSPENMVTFSENHGVVIQPAYKDKINITQLG--LQNSTI 131
Cdd:cd20989   3 VQVPPE-VRGFLGGSVTLPCHLLppnMVTHVSQVTWQRHD--EHGSVAVFHPKQGPSFPESERLSFVAARLGaeLRNASL 79

                        90       100       110
                ....*....|....*....|....*....|...
gi 90903245 132 TFWNITLEDEGCYMCLFNTFGFGKISGTACLTV 164
Cdd:cd20989  80 AMFGLRVEDEGNYTCEFATFPQGSRSGDTWLRV 112

First immunoglobulin variable (IgV) domain of nectin-3 (also known as poliovirus receptor related protein 3), and similar domains; The members here are composed of the first immunoglobulin (Ig) domain of nectin-3 (also known as poliovirus receptor related protein 3 (PVRL3) or cluster of differentiation (CD) 113). Nectin-3 belongs to the nectin family comprised of four transmembrane glycoproteins (nectins-1 through -4). Nectins are synaptic cell adhesion molecules (CAMs) which participate in adhesion and signaling at various intracellular junctions. Nectins form homophilic cis-dimers, followed by homophilic and heterophilic trans-dimers involved in cell-cell adhesion. For example, during spermatid development, the nectin-3,-2 trans-interaction is required for the formation of Sertoli cell-spermatid junctions in testis, and during morphogenesis of the ciliary body, the nectin-3,-1 trans-interaction is important for apex-apex adhesion between the pigment and non-pigment layers of the ciliary epithelia. Nectins also heterophilically trans-interact with other CAMs such as nectin-like molecules (Necls); nectin-3 for example, trans-interacts with Necl-5, regulating cell movement and proliferation. Other proteins with which nectin-3 interacts include the actin filament-binding protein, afadin, integrin alpha-beta3, Par-3, and PDGF receptor; its interaction with PDGF receptor regulates the latter's signaling for anti-apoptosis.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90903245  73 SLKCSLQNAQEALIVTWQKKKAVSPENMVTFSENHGVVIQPAYKDKINITQLGLQNSTITFWNITLEDEGCYMCLFNTFG 152
Cdd:cd05887  18 SLKCLIEVNETITQISWEKIHGKSSQTVAVHHPQYGISIQGEYQGRVSFKNYSLNDATITLHNVGFSDSGKYICKAVTFP 97

                        90
                ....*....|..
gi 90903245 153 FGKISGTACLTV 164
Cdd:cd05887  98 LGNAQSSTTVTV 109

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 90903245    72 ASLKCSLQNAQEALIVTWQKKKAVSPENMvtfsenhgvviqpaykdKINITQLGLQNSTITFWNITLEDEGCYMCLFNTF 151
Cdd:pfam00047  14 ATLTCSASTGSPGPDVTWSKEGGTLIESL-----------------KVKHDNGRTTQSSLLISNVTKEDAGTYTCVVNNP 76

                          90
                  ....*....|
gi 90903245   152 GFGKISGTAC 161
Cdd:pfam00047  77 GGSATLSTSL 86

First immunoglobulin variable (IgV) domain of DNAX accessory molecule 1, and similar domains; The members here are composed of the first immunoglobulin (Ig) domain of DNAX accessory molecule 1 (DNAM-1, also known as CD226). DNAM-1 is a transmembrane protein having two Ig-like domains. It is an adhesion molecule which plays a part in tumor-directed cytotoxicity and adhesion in natural killer (NK) cells and T lymphocytes. It has been shown to regulate the NK cell killing of several tumor types, including myeloma cells and ovarian carcinoma cells. DNAM-1 interacts specifically with poliovirus receptor (PVR; CD155) and nectin -2 (CD211), other members of the Ig superfamily. DNAM-1 is expressed in most peripheral T cells, NK cells, monocytes and a subset of B lymphocytes.

                        10        20        30        40        50        60        70        80
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90903245  73 SLKCSLQNAQEALIVTWQKKKAVSpENMVTFSENHGVVIQPAYKDKINI--TQLGLQNSTITFWNITLEDEGCYMCLFNT 150
Cdd:cd05889  18 SLECVYPSTGILTQVEWTKIGGQK-DNIAVYHPTHGMHIRKPYAGRVYFlnSTMASNNMSLSFRNASEDDVGYYSCSLYT 96

                .
gi 90903245 151 F 151
Cdd:cd05889  97 Y 97

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

                           10        20        30        40        50        60
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 90903245     96 SPENMVTFSENHGVVIqpAYKDKINITQLGlQNSTITFWNITLEDEGCYMCLFnTFGFGKISGTACLTV 164
Cdd:smart00410  21 SPPPEVTWYKQGGKLL--AESGRFSVSRSG-STSTLTISNVTPEDSGTYTCAA-TNSSGSASSGTTLTV 85

Second immunoglobulin (Ig) domain of nectin-3 and nectin-4 (poliovirus receptor related protein 4), and similar domains; member of the C1-set of Ig superfamily (IgSF) domains; The members here are composed of the second immunoglobulin (Ig) domain of nectin-3 (also known as poliovirus receptor related protein 3 or cluster of differentiation (CD) 113) and nectin-4 (poliovirus receptor related protein 4). Nectin-3 and nectin-4 belong to the nectin family comprised of four transmembrane glycoproteins (nectin-1 through -4). Nectins are synaptic cell adhesion molecules (CAMs) which facilitate adhesion and signaling at various intracellular junctions. Nectins form homophilic cis-dimers, followed by homophilic and heterophilic trans-dimers involved in cell-cell adhesion. Nectin-2 and nectin-3 localize at Sertoli-spermatid junctions where they form heterophilic trans-interactions between the cells that are essential for the formation and maintenance of the junctions and for spermatid development. Nectin-3 has also been shown to form a heterophilic trans-interaction with nectin-1 in ciliary epithelia, establishing the apex-apex adhesion between the pigment and non-pigment cell layers. Nectin-4 has recently been identified in several types of breast carcinoma and can be used as a histological and serological marker for breast cancer.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 90903245 184 TCSA-TARPAPMVFWKVPRSGIEnSTVTLSHPNgTTSVTSILHIKDPKNQVGKEVICQVLHLGTVTDFKQT 253
Cdd:cd07704  23 SCTAeTGKPAASVTWETDLGGME-SSRTFEHNR-TATVTSEYHLVPTRFANGRPLTCVVSHPALQQDIRIT 91

BARF1; Provisional

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90903245   81 AQEALIVTWQKKKAVSPENMVTFSE----NHGVVIQPAYKDKINITQ-----LGLQNSTITFWNI----TLEDEGCYMCL 147
Cdd:PHA03376  26 GERVTLTSYWRRVSLGPEIEVSWFKlgpgEEQVLIGRMHHDVIFIEWpfrgfFDIHRSANTFFLVvtaaNISHDGNYLCR 105

                         90       100       110       120       130       140       150       160
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 90903245  148 FNtFGFGKISGTACLTVyVQPI-VSLHYKFSE----DHLNITCSATARPAPMVFWKVPRSGIENSTVT----LSHPNGTT 218
Cdd:PHA03376 106 MK-LGETEVTKQEHLSV-VKPLtLSVHSERSQfpdfSVLTVTCTVNAFPHPHVQWLMPEGVEPAPTAAnggvMKEKDGSL 183

                        170
                 ....*....|.
gi 90903245  219 SVTSILHIKDP 229
Cdd:PHA03376 184 SVAVDLSLPKP 194

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.

                        10        20        30        40        50        60
                ....*....|....*....|....*....|....*....|....*....|....*....|.
gi 90903245 181 LNITCSATARPAPMVFWKVPRSGIENSTVtlsHPNGTTSVTSILHIKDPKNQVGKEVICQV 241
Cdd:cd00096   1 VTLTCSASGNPPPTITWYKNGKPLPPSSR---DSRRSELGNGTLTISNVTLEDSGTYTCVA 58