title: H2-M3, a full-service class Ib histocompatibility antigen.
abstract: 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.
authors.affiliation: Howard Hughes Medical Institute, Departments of Microbiology and Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235-9050, USA.
authors.forename: K F
authors.initials: KF
authors.lastname: Lindahl
authors.forename: D E
authors.initials: DE
authors.lastname: Byers
authors.forename: V M
authors.initials: VM
authors.lastname: Dabhi
authors.forename: R
authors.initials: R
authors.lastname: Hovik
authors.forename: E P
authors.initials: EP
authors.lastname: Jones
authors.forename: G P
authors.initials: GP
authors.lastname: Smith
authors.forename: C R
authors.initials: CR
authors.lastname: Wang
authors.forename: H
authors.initials: H
authors.lastname: Xiao
authors.forename: M
authors.initials: M
authors.lastname: Yoshino
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017951:Antigen Presentation; D003001:Cloning, Molecular; D015395:Histocompatibility Antigens Class I / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008024:Ligands; D051379:Mice; D008958:Models, Molecular; D015394:Molecular Structure; D009154:Mutation; D010455:Peptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology
chemical_list: D015395:Histocompatibility Antigens Class I; D008024:Ligands; D010455:Peptides