Download MendeleyCrystal structures of MHC class I complexes reveal the elusive intermediate conformations explored during peptide editing.
Li, L., Peng, X., Batliwala, M., Bouvier, M.(2023) Nat Commun 14: 5020-5020
- PubMed: 37596268
- DOI: https://doi.org/10.1038/s41467-023-40736-6
- Primary Citation of Related Structures:
8E13, 8E2Z, 8E8I, 8EC5 - PubMed Abstract:
Studies have suggested that MHC class I (MHC I) molecules fluctuate rapidly between numerous conformational states and these motions support peptide sampling. To date, MHC I intermediates are largely uncharacterized experimentally and remain elusive. Here, we present x-ray crystal structures of HLA-B8 loaded with 20mer peptides that show pronounced distortions at the N-terminus of the groove. Long stretches of N-terminal amino acid residues are missing in the electron density maps creating an open-ended groove. Our structures also reveal highly unusual features in MHC I-peptide interaction at the N-terminus of the groove. Molecular dynamics simulations indicate that the complexes have varying degrees of conformational flexibility in a manner consistent with the structures. We suggest that our structures have captured the remarkable molecular dynamics of MHC I-peptide interaction. The visualization of peptide-dependent conformational motions in MHC I is a major step forward in our conceptual understanding of dynamics in high-affinity peptide selection.
Organizational Affiliation:
Department of Microbiology and Immunology, University of Illinois, Chicago, IL, 60612, USA.
