DRB1(*)1316: Evolutionary and functional implications of a novel polymorphism at codon 86

HLA-DRB1 molecules contain extensive polymorphism localized to specific functional regions of the antigen binding sire (ABS). Position 86 of HLA-DRB1 molecules modulates a hydrophobic pocket in the ABS which acts as a peptide anchoring site [1]. We report the nucleotide sequence of HLA-DRB1*1316 which is identical co HLA-DRB1*1301 and *1302 except at codon 86. The novel allele encodes aspartate rather than valine or glycine at position 86. Val(86) and Gly(86) have been exclusively observed in thousands of oligotyped specimens; thus Asp(86) is a rare polymorphism which is significant with respect to hypotheses concerning evolution and structure-function relationships of HLA-DRB1 molecules.