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.

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gi 98985801  25 PIEELEDRVFVNCN--TSITWVEGTVGTLLSDITRLDLGKRILDPRGIYRCNGTDiykDKESTVQVHYR 91
Cdd:cd07691   1 SVKENEDKVFLKCNsaSSITWKKGTEGIEASDKTDLDLGSRINDPRGTYQCKGSE---NKEKTLQVHYR 66

Immunoglobulin (Ig)-like domain of Cluster of Differentiation (CD) 3 gamma and delta chains; member of the C1-set of IgSF domains; The members here are composed of immunoglobulin (Ig)-like domain of Cluster of Differentiation (CD) 3 gamma and delta chains. 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.

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gi 98985801  25 PIEELEDRVFVNCN--TSITWVEGTVGTLLSDITRLDLGKRILDPRGIYRCNGTDiykDKESTVQVHYR 91
Cdd:cd07691   1 SVKENEDKVFLKCNsaSSITWKKGTEGIEASDKTDLDLGSRINDPRGTYQCKGSE---NKEKTLQVHYR 66

Immunoreceptor tyrosine-based activation motif; T cell receptor (TCR) is a complex multi-protein cell surface receptor composed of the ligand-sensing TCR heterodimer and three signaling subunits. These signaling subunits contain cytoplasmic immunoreceptor tyrosine-based activation motifs (ITAMs) with a consensus sequence of YxxL/Ix6-12YxxL/I. The two tyrosines are phosphorylated by a Src kinase, Lck or Fyn. Binding of the dually phosphorylated ITAM peptide reorients the two SH2 domains relative to each other, destabilizing inhibitory interactions made by the linker connecting the SH2 and kinase domains.

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gi 98985801   102 DQVYQPLRDRDDAQYSHLGG 121
Cdd:pfam02189   1 DQLYQPLNKRDDDTYSHLGM 20

Immunoglobulin (Ig)-like domain of Cluster of Differentiation (CD) 3 gamma and delta chains; member of the C1-set of IgSF domains; The members here are composed of immunoglobulin (Ig)-like domain of Cluster of Differentiation (CD) 3 gamma and delta chains. 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.

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                ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 98985801  25 PIEELEDRVFVNCN--TSITWVEGTVGTLLSDITRLDLGKRILDPRGIYRCNGTDiykDKESTVQVHYR 91
Cdd:cd07691   1 SVKENEDKVFLKCNsaSSITWKKGTEGIEASDKTDLDLGSRINDPRGTYQCKGSE---NKEKTLQVHYR 66

Immunoreceptor tyrosine-based activation motif; T cell receptor (TCR) is a complex multi-protein cell surface receptor composed of the ligand-sensing TCR heterodimer and three signaling subunits. These signaling subunits contain cytoplasmic immunoreceptor tyrosine-based activation motifs (ITAMs) with a consensus sequence of YxxL/Ix6-12YxxL/I. The two tyrosines are phosphorylated by a Src kinase, Lck or Fyn. Binding of the dually phosphorylated ITAM peptide reorients the two SH2 domains relative to each other, destabilizing inhibitory interactions made by the linker connecting the SH2 and kinase domains.

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gi 98985801   102 DQVYQPLRDRDDAQYSHLGG 121
Cdd:pfam02189   1 DQLYQPLNKRDDDTYSHLGM 20