Fig. 1: The conformational populations of gp33, V3P, Y4F, and PF peptides, calculated by ensemble refinement, unveil dynamic information from crystal structures.

Stick representation of the peptides bound to the MHC. a Full-color peptides represent the peptide conformation before TCR binding in the crystallographic structure. In contrast, transparent peptides represent the conformation that the peptides assume after TCR binding. No crystallographic data are available for H-2D^b/Y4F/P14. The arrows indicate the changes in sidechain conformation. b Polymorphic peptide conformations of gp33, V3P, Y4F, and PF of the TCR-unbound pMHC complex calculated by ensemble refinement. The arrows indicate variations in the conformation of the sidechain. c After TCR binding, the peptides rigidify, and all peptide ensembles assume the same restricted conformation. No crystallographic data are available for H-2D^b/Y4F/P14. d Concerted and opposing motions between H155 and p6F sidechains were observed in the TCR-unbound pMHC complexes, particularly in H-2D^b/gp33 and H-2D^b/PF. H-2D^b (white) is shown in cartoon representation and the H155 sidechain is shown in stick representation.