Fig. 2: Comparison of Mylu-B*67:01 and Mylu-B*67:01ΔMQQPW peptide binding capacity and crystal structures formed with P1-F/T/E, respectively.

a Comparison of the complex formation between Mylu-B*67:01 and Mylu-B*67:01ΔMQQPW with R9Ps through in vitro refolding. b The PBM of Mylu-B*67:01ΔMQQPW determined by RPLD-MS. c Differential comparison of the PBMs of Mylu-B*67:01 and Mylu-B*67:01ΔMQQPW. d Comparison of in vitro refolding products of Mylu-B*67:01 and Mylu-B*67:01ΔMQQPW with P1 peptide and its mutant peptides, respectively. The thermal stabilities of these complexes were also compared by the Tm values determined by CD experiment. e Comparison of the solved pMylu-B*67:01 and pMylu-B*67:01ΔMQQPW structures. Peptides P1-F and P1-T bind with Mylu-B*67:01 and Mylu-B*67:01ΔMQQPW in an identical pattern. The primary structural differences are localized in the region surrounding the insertion of the MQQPW sequence. f The unbiased 2Fo-Fc electron density maps of the inserted MQQPW in three solved pMylu-B*67:01 structures (contoured at 1.0 sigma). After the deletion of MQQPW, these three structures were refined using phenix.composite_omit_map, and subsequently, the unbiased 2Fo-Fc electron density maps were displayed using PyMOL to assess the fit of the sticks of MQQPW. The correlation coefficient values between map and model for the inserted MQQPW of the structures are 0.7910, 0.7990, and 0.7610, respectively. The clear matching results substantiate the credibility of the structural changes caused by MQQPW.