CD79 is a dimer formed by the combination of a 34kDa α chain (encoded by the gene on chromosome 19) and a 39kDa β chain (encoded by the gene on chromosome 17) through disulfide bonds. CD79 binds non-covalently with surface immunoglobulins to form the B-cell receptor.
CD79 is a typical B-cell antigen, with the α chain appearing in the cytoplasm before the mu heavy chain during B-cell development; some authors suggest even before CD19. The β chain appears later in the cytoplasm of B-cell precursors, usually forming a complex on the B-cell surface with the α chain after the appearance of the mu chain, co-expressing with Ig.
