Definition of Hla-a

HLA-A an (human leukocyte antigen) belongs to the MHC class I heavy chain receptors. The HLA-A is a heterodimeric receptor consisting of a HLA-A mature gene product and β2-microglobulin. The mature A chain is anchored in the membrane. MHC Class I molecules, like HLA-A, are expressed in nearly all cells, and present small peptides to the immune system which surveys for non-self peptides. As in most mammalian populations, MHC Class I molecules are extremely variable in their primary structure, and HLA-A is rank amoung the genes in humans with the fastest evolving coding sequence. After typing millions of individuals, as of 10/15/2007 617 variant alleles have been identified, encoding for 486 protien isoforms.