Immunoglobulin variable domain (IgV) Cluster of Differentiation (CD) 79B
The members here are composed of the immunoglobulin variable domain (IgV) of the Cluster of Differentiation (CD) 79B (also known as CD79b molecule, immunoglobulin-associated beta (Ig-beta), and B29). The B lymphocyte antigen receptor is a multimeric complex that includes the antigen-specific component, surface immunoglobulin (Ig). Surface Ig non-covalently associates with two other proteins, Ig-alpha and Ig-beta, which are necessary for expression and function of the B-cell antigen receptor. This gene encodes the Ig-beta protein of the B-cell antigen component. Alternatively spliced transcript variants encoding different isoforms have been described. Members of the IgV family are components of immunoglobulin (Ig) and T cell receptors. The basic structure of Ig molecules is a tetramer of two light chains and two heavy chains linked by disulfide bonds. In Ig, each chain is composed of one variable domain (IgV) and one or more constant domains (IgC); these names reflect the fact that the variability in sequences is higher in the variable domain than in the constant domain. Within the variable domain, there are regions of even more variability called the hypervariable or complementarity-determining regions (CDRs) which are responsible for antigen binding. A predominant feature of most Ig domains is the disulfide bridge connecting 2 beta-sheets with a tryptophan residue packed against the disulfide bond. Members of this group contain standard Ig superfamily V-set AGFCC'C"/DEB domain topology.
Jiyao W et al.(2023). "The conserved domain database in 2023.",