Bound water structure and polymorphic amino acids act together to allow the binding of different peptides to MHC class I HLA-B53

Immunity. 1996 Mar;4(3):215-28. doi: 10.1016/s1074-7613(00)80430-6.

Abstract

The structure of the human MHC class I molecule HLA-B53 complexed to two nonameric peptide epitopes (from the malaria parasite P. falciparum and the HIV2 gag protein) has been determined by X-ray crystallography at 2.3 angstrom resolution. The structures reveal the architecture of a Pro-specific B pocket common to many HLA-B alleles. Relative to other alleles, the B53 peptide-binding groove is widened by a significant (up to 1.25 angstrom) shift in the position of the alpha 1 helix. Within this groove, bound water molecules, acting in concert with the side chains of polymorphic residues, provide the functional malleability of the MHC, which enables the high affinity/low specificity binding of multiple peptide epitopes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Amino Acids / chemistry*
  • Base Sequence
  • Crystallography, X-Ray
  • HLA Antigens / chemistry*
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Peptides / chemistry*
  • Polymorphism, Genetic / immunology*
  • Protein Binding / immunology
  • Protein Conformation
  • Structure-Activity Relationship
  • Water / chemistry*

Substances

  • Amino Acids
  • HLA Antigens
  • HLA-B53 antigen
  • Peptides
  • Water

Associated data

  • PDB/UNKNOWN