H2-M3, a full-service class Ib histocompatibility antigen.
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.
Lindahl
K F
KF
Howard Hughes Medical Institute, Departments of Microbiology and Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235-9050, USA.
Byers
D E
DE
Dabhi
V M
VM
Hovik
R
R
Jones
E P
EP
Smith
G P
GP
Wang
C R
CR
Xiao
H
H
Yoshino
M
M
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
D015395:Histocompatibility Antigens Class I; D008024:Ligands; D010455:Peptides