Summary: CD80-like C2-set immunoglobulin domain
This is the Wikipedia entry entitled "Immunoglobulin C2-set domain". More...
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Immunoglobulin C2-set domain Edit Wikipedia article
|Immunoglobulin C2-set domain|
The basic structure of immunoglobulin (Ig) molecules is a tetramer of two light chains and two heavy chains linked by disulphide bonds. There are two types of light chains: kappa and lambda, each composed of a constant domain (CL) and a variable domain (VL). There are five types of heavy chains: alpha, delta, epsilon, gamma and mu, all consisting of a variable domain (VH) and three (in alpha, delta and gamma) or four (in epsilon and mu) constant domains (CH1 to CH4). Ig molecules are highly modular proteins, in which the variable and constant domains have clear, conserved sequence patterns. The domains in Ig and Ig-like molecules are grouped into four types: V-set (variable; IPR013106), C1-set (constant-1; IPR003597), C2-set (constant-2; IPR008424) and I-set (intermediate; IPR013098). Structural studies have shown that these domains share a common core Greek-key beta-sandwich structure, with the types differing in the number of strands in the beta-sheets as well as in their sequence patterns.
Immunoglobulin-like domains that are related in both sequence and structure can be found in several diverse protein families. Ig-like domains are involved in a variety of functions, including cell–cell recognition, cell-surface receptors, muscle structure and the immune system.
C2-set domains, which are Ig-like domains resembling the antibody constant domain. C2-set domains are found primarily in the mammalian T-cell surface antigens CD2 (Cluster of Differentiation 2), CD4 and CD80, as well as in vascular (VCAM) and intercellular (ICAM) cell adhesion molecules.
CD2 mediates T-cell adhesion via its ectodomain, and signal transduction utilising its 117-amino acid cytoplasmic tail. CD2 displays structural and functional similarities with African swine fever virus (ASFV) LMW8-DR, a protein that is involved in cell–cell adhesion and immune response modulation, suggesting a possible role in the pathogenesis of ASFV infection. CD4 is the primary receptor for HIV-1. CD4 has four immunoglobulin-like domains in its extracellular region that share the same structure, but can differ in sequence. Certain extracellular domains may be involved in dimerisation.
- Smith DK, Xue H (1997). "Sequence profiles of immunoglobulin and immunoglobulin-like domains". J. Mol. Biol. 274 (4): 530–545. doi:10.1006/jmbi.1997.1432. PMID 9417933.
- Potapov V, Sobolev V, Edelman M, Kister A, Gelfand I (2004). "Protein-Protein Recognition: Juxtaposition of Domain and Interface Cores in Immunoglobulins and Other Sandwich-like Proteins". J. Mol. Biol. 342 (2): 665–679. doi:10.1016/j.jmb.2004.06.072. PMID 15327963.
- Clarke J, Fowler SB (2001). "Mapping the folding pathway of an immunoglobulin domain: structural detail from Phi value analysis and movement of the transition state". Structure 9 (5): 355–366. doi:10.1016/S0969-2126(01)00596-2. PMID 11377196.
- Chothia C, Teichmann SA (2000). "Immunoglobulin superfamily proteins in Caenorhabditis elegans". J. Mol. Biol. 296 (5): –. doi:10.1006/jmbi.1999.3497. PMID 10698639.
- Reinherz EL, Yang H (2001). "Dynamic recruitment of human CD2 into lipid rafts. Linkage to T cell signal transduction". J. Biol. Chem. 276 (22): 18775–18785. doi:10.1074/jbc.M009852200. PMID 11376005.
- Kutish GF, Rock DL, Afonso CL, Borca MV, Irusta P, Carrillo C, Brun A, Sussman M (1994). "An African swine fever virus gene with similarity to the T-lymphocyte surface antigen CD2 mediates hemadsorption". Virology 199 (2): 463–468. doi:10.1006/viro.1994.1146. PMID 7907198.
- Sanejouand YH (2004). "Domain swapping of CD4 upon dimerization". Proteins 57 (1): –. doi:10.1002/prot.20197. PMID 15326605.
Human proteins containing this domain
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CD80-like C2-set immunoglobulin domain Provide feedback
These domains belong to the immunoglobulin superfamily.
Internal database links
|Similarity to PfamA using HHSearch:||ig Marek_A C1-set I-set Ig_2 Ig_3|
External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR013162
The basic structure of immunoglobulin (Ig) molecules is a tetramer of two light chains and two heavy chains linked by disulphide bonds. There are two types of light chains: kappa and lambda, each composed of a constant domain (CL) and a variable domain (VL). There are five types of heavy chains: alpha, delta, epsilon, gamma and mu, all consisting of a variable domain (VH) and three (in alpha, delta and gamma) or four (in epsilon and mu) constant domains (CH1 to CH4). Ig molecules are highly modular proteins, in which the variable and constant domains have clear, conserved sequence patterns. The domains in Ig and Ig-like molecules are grouped into four types: V-set (variable; INTERPRO), C1-set (constant-1; INTERPRO), C2-set (constant-2; INTERPRO) and I-set (intermediate; INTERPRO) [PUBMED:9417933]. Structural studies have shown that these domains share a common core Greek-key beta-sandwich structure, with the types differing in the number of strands in the beta-sheets as well as in their sequence patterns [PUBMED:15327963, PUBMED:11377196].
Immunoglobulin-like domains that are related in both sequence and structure can be found in several diverse protein families. Ig-like domains are involved in a variety of functions, including cell-cell recognition, cell-surface receptors, muscle structure and the immune system [PUBMED:10698639].
This entry represents the C2-set type domains found in the T-cell antigen CD80, as well as in related proteins. CD80 (B7-1) is a glycoprotein expressed on antigen-presenting cells [PUBMED:10661405]. The shared ligands on CD80 and CD86 (B7-2) deliver the co-stimulatory signal through CD28 and CTLA-4 on T-cells, where CD28 augments the T-cell response and CTLA-4 attenuates it [PUBMED:11279502].
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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. The superfamily can be divided into discrete structural sets, by the presence or absence of beta-strands in the structure and the length of the domains . Proteins containing domains of the C1 and V-sets are mostly molecules of the vertebrate immune system. Proteins of the C2-set are mainly lymphocyte antigens, this differs from the composition of the C2-set as originally proposed . The I-set is intermediate in structure between the C1 and V-sets and is found widely in cell surface proteins as well as intracellular muscle proteins.
The clan contains the following 24 members:A2M Adeno_E3_CR1 Adhes-Ig_like C1-set C2-set C2-set_2 Herpes_gE Herpes_gI Herpes_glycop_D I-set ICAM_N ig Ig_2 Ig_3 Ig_Tie2_1 IZUMO K1 Lep_receptor_Ig Marek_A PTCRA Receptor_2B4 SVA V-set V-set_CD47
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Curation and family details
|Seed source:||Pfam-B_280 (release 17.0)|
|Number in seed:||33|
|Number in full:||3971|
|Average length of the domain:||86.30 aa|
|Average identity of full alignment:||17 %|
|Average coverage of the sequence by the domain:||19.89 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||7|
|Download:||download the raw HMM for this family|
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There is 1 interaction for this family. More...
We determine these interactions using iPfam, which considers the interactions between residues in three-dimensional protein structures and maps those interactions back to Pfam families. You can find more information about the iPfam algorithm in the journal article that accompanies the website.
For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the C2-set_2 domain has been found. There are 29 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein seqence.
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