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Protein Domain : IPR003006

Name  Immunoglobulin/major histocompatibility complex, conserved site Short Name  Ig/MHC_CS
Type  Conserved_site Description  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; ), C1-set (constant-1; ), C2-set (constant-2; ) and I-set (intermediate; ) []. 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 []. Major Histocompatibility Complex (MHC) glycoproteins are heterodimeric cell surface receptors that function to present antigen peptide fragments to T cells responsible for cell-mediated immune responses. MHC molecules can be subdivided into two groups on the basis of structure and function: class I molecules present intracellular antigen peptide fragments (~10 amino acids) on the surface of the host cells to cytotoxic T cells; class II molecules present exogenously derived antigenic peptides (~15 amino acids) to helper T cells. MHC class I and II molecules are assembled and loaded with their peptide ligands via different mechanisms. However, both present peptide fragments rather than entire proteins to T cells, and are required to mount an immune response.Some of the proteins in this group are responsible for the molecular basis of the blood group antigens, surface markers on the outside of the red blood cell membrane. Most of these markers are proteins, but some are carbohydrates attached to lipids or proteins [Reid M.E., Lomas-Francis C. The Blood Group Antigen FactsBook Academic Press, London / San Diego, (1997)]. Lutheran blood group glycoprotein (B-CAM cell surface glycoprotein) (Auberger B antigen) (F8/G253 antigen) belongs to the Lutheran blood group system and is associated with Lu(a/b), Au(a/b), LU6 to LU20 antigens. More information about these proteins can be found at Protein of the Month: MHC [].

Publication Counts Displayer

0 Child Features

0 Contains

1 Cross References

Source . Name

Subject . Primary Identifier
PS00290 PROSITE IPR003006

2 Data Sets

Name URL
TrEMBL data set
InterPro data set  

4 Found In

DB identifier Name Short Name Type
IPR013783 Immunoglobulin-like fold Ig-like_fold Domain
IPR007110 Immunoglobulin-like domain Ig-like_dom Domain
IPR003597 Immunoglobulin C1-set Ig_C1-set Domain
IPR015707 Beta-2-Microglobulin B2Microglobulin Family

0 GO Annotation

0 Ontology Annotations

0 Parent Features

16 Proteins

DB identifier Primary Accession
Organism . Name
FBpp0086544 Q8MRA3 Drosophila melanogaster
FBpp0086545 A1Z9X4 Drosophila melanogaster
FBpp0277957 Q28ZM3 Drosophila pseudoobscura
FBpp0167928 B4KP29 Drosophila mojavensis
FBpp0168142 B4KTR8 Drosophila mojavensis
FBpp0172107 B4K6V4 Drosophila mojavensis
FBpp0232257 B4MHH1 Drosophila virilis
FBpp0237721 B4LYV9 Drosophila virilis
FBpp0258639 B4P7S8 Drosophila yakuba
A8XKC0_CAEBR A8XKC0 Caenorhabditis briggsae
A8XYX1_CAEBR A8XYX1 Caenorhabditis briggsae
G0MQF6_CAEBE G0MQF6 Caenorhabditis brenneri
Q9NAA0_CAEEL Q9NAA0 Caenorhabditis elegans
Q22125_CAEEL Q22125 Caenorhabditis elegans
Q9V787_DROME Q9V787 Drosophila melanogaster
E3LE50_CAERE E3LE50 Caenorhabditis remanei