Characterization of the peptide-binding specificity of HLA-B*7301.
Previous studies showed the human MHC class I heavy chain HLA-B*7301 has a sequence very divergent from other class I alleles. Despite the unusual sequence, we predicted B*7301 would retain the peptide-binding function typical of other HLA-A, B and C glycoproteins, and sequence similarity to B*2705 in a region of the peptide-binding site known as the B pocket suggested B*7301 would bind peptides with Arg at position 2. To test this hypothesis, the peptide-binding specificity of B*7301 was investigated. Sequence analysis of peptides bound endogenously by B*7301 indeed found selectivity for nonamer peptides possessing Arg at position 2 and a preference for small nonpolar residues such as Pro or Ala at the C terminus was also revealed. B*7301 therefore possesses the potential to function as a conventional antigen presenting class I glycoprotein. Functional similarities between B*7301 and B*2705 are discussed in the context of the association of B*27 subtypes with susceptibility to ankylosing sponylitis and arthritic diseases.
Barber
L D
LD
Department of Structural Biology, Stanford University, California, USA.
Percival
L
L
Parham
P
P
D001665:Binding Sites; D002461:Cell Line, Transformed; D015235:HLA-B Antigens / Q000276:immunology*; D006801:Humans; D010455:Peptides / Q000737:chemistry / Q000276:immunology*
D015235:HLA-B Antigens; D010455:Peptides