Description
HLA Class II Histocompatibility Antigen DR β 5 Chain (HLA-DRB5) is a single-pass type I membrane protein that belongs to the MHC class II family. HLA-DRB5 contains one Ig-like C1-type domain. The class II molecule is a heterodimer consisting of an α (DRA) and a β chain (DRB), both anchored in the membrane. HLA-DRB5 plays a central role in the immune system by presenting peptides derived from extracellular proteins. Class II molecules are expressed in antigen presenting cells. Within the DR molecule, the β chain contains all the polymorphisms specifying the peptide binding specificities. Typing for these polymorphisms is routinely done for bone marrow and kidney transplantation. The presence of DRB5 is linked with allelic variants of DRB1, otherwise it is omitted