Immunoglobulin (Ig)-like domain of Cluster of Differentiation (CD) 3 epsilon chain; member of the C1-set of IgSF domains; The members here are composed of the immunoglobulin (Ig)-like domain of Cluster of Differentiation (CD) 3 epsilon chain. CD3 is a T cell surface receptor that is associated with alpha/beta T cell receptors (TCRs). The CD3 complex consists of one gamma, one delta, two epsilon, and two zeta chains. The CD3 subunits form heterodimers as gamma/epsilon, delta/epsilon, and zeta/zeta. The gamma, delta, and epsilon chains each contain an extracellular Ig domain, whereas the extracellular domains of the zeta chains are very small and have unknown structure. The CD3 domain participates in intracellular signaling once the TCR has bound an MHC/antigen complex.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 57164265  30 YEVSISGNSVELTCPKDFENGIQWKR--NNEQMKGHNEKYLLLDQFSEMESSGYYQCLATEGNTEAAHTLYLKAR 102
Cdd:cd07692   1 YKVSISGTSVELTCPKDFENGIQWKRndNNEQMKGHNEKYLSLKEFSEMESSGYYQCYATEGNTEAAHYLYLRAR 75

Immunoglobulin (Ig)-like domain of Cluster of Differentiation (CD) 3 epsilon chain; member of the C1-set of IgSF domains; The members here are composed of the immunoglobulin (Ig)-like domain of Cluster of Differentiation (CD) 3 epsilon chain. CD3 is a T cell surface receptor that is associated with alpha/beta T cell receptors (TCRs). The CD3 complex consists of one gamma, one delta, two epsilon, and two zeta chains. The CD3 subunits form heterodimers as gamma/epsilon, delta/epsilon, and zeta/zeta. The gamma, delta, and epsilon chains each contain an extracellular Ig domain, whereas the extracellular domains of the zeta chains are very small and have unknown structure. The CD3 domain participates in intracellular signaling once the TCR has bound an MHC/antigen complex.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 57164265  30 YEVSISGNSVELTCPKDFENGIQWKR--NNEQMKGHNEKYLLLDQFSEMESSGYYQCLATEGNTEAAHTLYLKAR 102
Cdd:cd07692   1 YKVSISGTSVELTCPKDFENGIQWKRndNNEQMKGHNEKYLSLKEFSEMESSGYYQCYATEGNTEAAHYLYLRAR 75

Immunoreceptor tyrosine-based activation motif; Motif that may be dually phosphorylated on tyrosine that links antigen receptors to downstream signalling machinery.

                           10        20
                   ....*....|....*....|.
gi 57164265    170 NPDYEPIRKGQRDLYSGLNQR 190
Cdd:smart00077   1 DQLYQPLNKRQRDTYSDLNTR 21

Immunoglobulin (Ig)-like domain of Cluster of Differentiation (CD) 3 epsilon chain; member of the C1-set of IgSF domains; The members here are composed of the immunoglobulin (Ig)-like domain of Cluster of Differentiation (CD) 3 epsilon chain. CD3 is a T cell surface receptor that is associated with alpha/beta T cell receptors (TCRs). The CD3 complex consists of one gamma, one delta, two epsilon, and two zeta chains. The CD3 subunits form heterodimers as gamma/epsilon, delta/epsilon, and zeta/zeta. The gamma, delta, and epsilon chains each contain an extracellular Ig domain, whereas the extracellular domains of the zeta chains are very small and have unknown structure. The CD3 domain participates in intracellular signaling once the TCR has bound an MHC/antigen complex.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 57164265  30 YEVSISGNSVELTCPKDFENGIQWKR--NNEQMKGHNEKYLLLDQFSEMESSGYYQCLATEGNTEAAHTLYLKAR 102
Cdd:cd07692   1 YKVSISGTSVELTCPKDFENGIQWKRndNNEQMKGHNEKYLSLKEFSEMESSGYYQCYATEGNTEAAHYLYLRAR 75

T-cell surface glycoprotein CD3 delta chain; This is an immunoglobulin-like domain. It is found on the T-cell surface glycoprotein CD3 delta chain. CD3delta and CD3epsilon complex together as part of the T-cell receptor complex.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 57164265    36 GNSVELTCPKDFENgIQWKRNNEQMKGHNEKYLLLDQFSEmESSGYYQClatEGNTEAAHTLYLKARV 103
Cdd:pfam16680   1 DGKVLLTCNSSSKS-ITWLKDGKGIKSTNTKTLDLGKFSE-DPRGLYQC---QGEKKKSSTLQVYYRM 63

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.

                        10        20        30        40        50        60        70
                ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....
gi 57164265  36 GNSVELTCPKD-F-ENGIQWKRNNEQMKGHNEKYLLLDQFSEM-------ESSGYYQCLATEGNTEAAHTLYLK 100
Cdd:cd05730  18 GQSVTLACDADgFpEPTMTWTKDGEPIESGEEKYSFNEDGSEMtildvdkLDEAEYTCIAENKAGEQEAEIHLK 91

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.

                        10        20        30        40        50
                ....*....|....*....|....*....|....*....|....*....|....*....
gi 57164265  36 GNSVELTC-PKDFENGIQWKRNNEQMKGHNEKYLLLDQ----FSEMES-SGYYQCLATE 88
Cdd:cd05873  11 GGNAELKCsPKSNLARVVWKFQGKVLKAESPKYGLYGDglliFNASEAdAGRYQCLSVE 69