Zooming in on the hydrophobic ridge of H-2D(b): implications for the conformational variability of bound peptides.Ciatto, C., Tissot, A.C., Tschopp, M., Capitani, G., Pecorari, F., Pluckthun, A., Grutter, M.G.
(2001) J.Mol.Biol. 312: 1059-1071
- PubMed: 11580250
- DOI: 10.1006/jmbi.2001.5016
- Primary Citation of Related Structures:
- PubMed Abstract:
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 natur ...
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.
Biochemisches Insitut, der Universität Zürich, Winterthurerstrasse 190, Zürich, CH-8057, Switzerland.