Extended Data Fig. 10: Crystal structure comparison of OppA and its homologs.
From: An oligopeptide permease, OppABCD, requires an iron–sulfur cluster domain for functionality
a, Cartoon and surface representations of aligned OppA (red) and Mtb DppA (blue, PDB: 6E3D). b, c, Clipped surface view of OppA and Mtb DppA, respectively. d, Interactions between Mtb DppA and its endogenous tetrapeptide. Conserved binding residues are labeled. Hydrogen bonds are indicated by yellow dashed lines. e, Surface representation of the binding cavity (light purple) of closed OppA. The endogenous oligopeptide is depicted in pink solid spheres for the Cα atoms. f, Structural alignment of Mtb OppA (red cartoons) and L. lactis OppA (green cartoons, PDB: 3DRG). The bound oligopeptides are also indicated as solid spheres. g, The binding mode of the endogenous oligopeptide in Mtb OppA. h, The binding mode of bradykinin in L. lactis OppA. In g and h, aromatic residues in the binding pocket are labeled.
