Structure of a SARS coronavirus-derived peptide bound to the human major histocompatibility complex class I molecule HLA-B*1501

The human leukocyte antigen (HLA) class I system comprises a highly polymorphic set of molecules that specifically bind and present peptides to cytotoxic T cells. HLA-B*1501 is a prototypical member of the HLA-B62 supertype and only two peptide-HLA-B*1501 structures have been determined. Here, the crystal structure of HLA-B*1501 in complex with a SARS coronavirus-derived nonapeptide (VQQESSFVM) has been determined at high resolution (1.87 Å). The peptide is deeply anchored in the B and F pockets, but with the Glu4 residue pointing away from the floor in the peptide-binding groove, making it available for interactions with a potential T-cell receptor.