Fig. 4

Three-dimensional ribbon models of the HLA proteins associated with OBI. The protein structures of HLA-DRB1 are based on Protein Data Bank (PDB) entries 1AQD. Antigen peptides are shown in blue which was previously shown to bind to HLA-DRB1*01:01. DR α chain is showed by green cyan, while β chain is showed by orange. The four critical residues Gln4β, Val57β(P9), Ser60β(P9) and Val78β(P4) are shown by yellow arrows. The residues in the binding groove of the HLA were selected by proximity (2.45 Å) to the peptide