H2-M3, a full-service class Ib histocompatibility antigen

Annu Rev Immunol. 1997;15:851-79. doi: 10.1146/annurev.immunol.15.1.851.


H2-M3 is an MHC class Ib molecule of the mouse with a unique preference for N-formylated peptides, which may come from the N-termini of endogenous, mitochondrial proteins or foreign, bacterial proteins. The crystal structure of M3 revealed a hydrophobic peptide-binding groove with an occluded A pocket and the peptide shifted one residue relative to class Ia structures. The formyl group is held by a novel hydrogen bonding network, involving His9 on the bottom of the groove, and the side chain of the P1 methionine is lodged in the B pocket. M3 is a full-service histocompatibility (H) antigen, i.e. self-M3 can present endogenous peptides as minor H antigens and foreign, bacterial antigens in a defensive immune response to infection; and foreign M3 complexed with endogenous self-peptides.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Antigen Presentation
  • Cloning, Molecular
  • Histocompatibility Antigens Class I / chemistry
  • Histocompatibility Antigens Class I / genetics
  • Histocompatibility Antigens Class I / metabolism*
  • Ligands
  • Mice
  • Models, Molecular
  • Molecular Structure
  • Mutation
  • Peptides / chemistry
  • Peptides / genetics
  • Peptides / metabolism
  • T-Lymphocytes / immunology
  • T-Lymphocytes / metabolism
  • T-Lymphocytes, Cytotoxic / immunology


  • Histocompatibility Antigens Class I
  • Ligands
  • Peptides