Download MendeleyCrystal structure of a TAPBPR-MHC I complex reveals the mechanism of peptide editing in antigen presentation.
Jiang, J., Natarajan, K., Boyd, L.F., Morozov, G.I., Mage, M.G., Margulies, D.H.(2017) Science 358: 1064-1068
- PubMed: 29025991
- DOI: https://doi.org/10.1126/science.aao5154
- Primary Citation of Related Structures:
5WER, 5WES, 5WET, 5WEU - PubMed Abstract:
Central to CD8 + T cell-mediated immunity is the recognition of peptide-major histocompatibility complex class I (p-MHC I) proteins displayed by antigen-presenting cells. Chaperone-mediated loading of high-affinity peptides onto MHC I is a key step in the MHC I antigen presentation pathway. However, the structure of MHC I with a chaperone that facilitates peptide loading has not been determined. We report the crystal structure of MHC I in complex with the peptide editor TAPBPR (TAP-binding protein-related), a tapasin homolog. TAPBPR remodels the peptide-binding groove of MHC I, resulting in the release of low-affinity peptide. Changes include groove relaxation, modifications of key binding pockets, and domain adjustments. This structure captures a peptide-receptive state of MHC I and provides insights into the mechanism of peptide editing by TAPBPR and, by analogy, tapasin.
Organizational Affiliation:
Molecular Biology Section, Laboratory of Immunology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
