2Q6W, 4H1L3125n/an/an/aP79483n/aNM_022555n/aNP_072049n/aHLA class II histocompatibility antigen, DRB3-1 beta chain is a protein that in humans is encoded by the HLA-DRB3 gene.

[2] The protein encoded by this gene belongs to the HLA class II beta chain paralogues.

The class II molecule is a heterodimer consisting of an alpha (DRA) and a beta chain (DRB), both anchored in the membrane.

It plays a central role in the immune system by presenting peptides derived from extracellular proteins.

Within the DR molecule the beta chain contains all the polymorphisms specifying the peptide binding specificities.