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A comprehensive mutational scan of the TAPBPR scoop loop defines a region of the sequence-activity landscape for class I MHC interactions

ABSTRACT: The loading of high affinity peptides onto nascent class I MHC (MHC-I) molecules is facilitated by chaperones, including the class I-specific chaperone TAP-binding protein-related (TAPBPR). TAPBPR features a ‘scoop’ loop that projects towards the empty MHC-I peptide binding groove and rests above the F pocket. The scoop loop is not found in the closely related homologue tapasin, and therefore may be partly responsible for the unique antigen editing properties of TAPBPR. A deep mutational scan of the TAPBPR scoop loop defines the relative effects of all single amino acid mutations on binding and peptide-mediated release of the murine H2-Dd MHC-I allomorph. Increased hydrophobic packing between the scoop loop and rim of the peptide binding groove tightens the TAPBPR-MHC-I interaction.

ORGANISM(S): synthetic construct

PROVIDER: GSE118568 | GEO | 2019/10/31

REPOSITORIES: GEO

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Critical residues within the TAPBPR scoop loop for HLA-A2 binding and peptide loading are determined by deep mutational scanning

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