A hypothetical model of the foreign antigen binding site of class II histocompatibility molecules

Nature. 1988 Apr 28;332(6167):845-50. doi: 10.1038/332845a0.


Class II and class I histocompatibility molecules allow T cells to recognize 'processed' polypeptide antigens. The two polypeptide chains of class II molecules, alpha and beta, are each composed of two domains (for review see ref. 6); the N-terminal domains of each, alpha 1 and beta 1, are highly polymorphic and appear responsible for binding peptides at what appears to be a single site and for being recognized by MHC-restricted antigen-specific T cells. Recently, the three-dimensional structure of the foreign antigen binding site of a class I histocompatibility antigen has been described. Because a crystal structure of a class II molecule is not available, we have sought evidence in class II molecules for the structural features observed in the class I binding site by comparing the patterns of conserved and polymorphic residues of twenty-six class I and fifty-four class II amino acid sequences. The hypothetical class II foreign-antigen binding site we present is consistent with mutation experiments and provides a structural framework for proposing peptide binding models to help understand recent peptide binding data.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Antibodies, Monoclonal
  • Binding Sites
  • Chemical Phenomena
  • Chemistry, Physical
  • Histocompatibility Antigens Class II*
  • Lymphocyte Activation
  • Models, Molecular*
  • T-Lymphocytes / immunology


  • Antibodies, Monoclonal
  • Histocompatibility Antigens Class II