The immunoglobulin domain is a type of protein domain that consists of a 2-layer sandwich of 7-9 antiparallel β-strands arranged in two β-sheets with a Greek key topology, consisting of about 125 amino acids.
The backbone switches repeatedly between the two β-sheets. Typically, the pattern is (N-terminal β-hairpin in sheet 1)-(β-hairpin in sheet 2)-(β-strand in sheet 1)-(C-terminal β-hairpin in sheet 2). The cross-overs between sheets form an "X", so that the N- and C-terminal hairpins are facing each other.
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 proteinâ€"protein and proteinâ€"ligand interactions.
Examples
Human genes encoding proteins containing the immunoglobulin domain include:
See also
- Immunoglobulin superfamily
References
External links
- SCOP listing of immunoglobulin domains of known structure
This article incorporates text from the public domain Pfam and InterPro IPR013151
