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Publication Abstract from PubMed

Class I major histocompatibility complex (MHC) molecules, which display intracellularly processed peptides on the cell surface for scanning by T-cell receptors (TCRs), are extraordinarily polymorphic. MHC polymorphism is believed to result from natural selection, since individuals heterozygous at the corresponding loci can cope with a larger number of pathogens. Here, we present the crystal structures of the murine MHC molecule H-2D(b) in complex with the peptides gp276 and np396 from the lymphocytic choriomeningitis virus (LCMV), solved at 2.18 A and 2.20 A resolution, respectively. The most prominent feature of H-2D(b) is a hydrophobic ridge that cuts across its antigen-binding site, which is conserved in the L(d)-like family of class I MHC molecules. The comparison with previously solved crystal structures of peptide/H-2D(b) complexes shows that the hydrophobic ridge focuses the conformational variability of the bound peptides in a "hot-spot", which could allow optimal TCR interaction and discrimination. This finding suggests a functional reason for the conservation of this structural element.

Zooming in on the hydrophobic ridge of H-2D(b): implications for the conformational variability of bound peptides.,Ciatto C, Tissot AC, Tschopp M, Capitani G, Pecorari F, Pluckthun A, Grutter MG J Mol Biol. 2001 Oct 5;312(5):1059-71. PMID:11580250^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.