Fig. 4: Probing conformational plasticity of the BamA barrel domain.

a A superposition of the inward-open and outward-open conformations of the barrel domain of BamA (middle). The left and right panels indicate the locations of crosslink mutations made in these studies, with the crosslinks designed to lock each specific conformation shown in yellow. The gray spheres indicate the locations of the crosslink mutant pairs in the opposite conformation, which are separated by 15–23 Å. b Plate assays using JCM166 cells transformed and plated onto LB agar plates with the C2S control and crosslink mutants locking each of the conformations designed in panel a. Each was performed at least in triplicate with representative images shown. c Analysis of the crosslink mutants by western blot on a 5% SDS-PAGE gel showing the direct observation of the crosslinked species (oxidized), which can be reduced in the presence of DTT. Assays were performed at least in triplicate with a representative image shown. Source data are provided as a Source Data file. d Surface shaving experiments with proteinase K (PK), followed by western blot analysis, verified each of the indicated mutants are surface exposed with no disruption in biogenesis. Assays were performed at least in triplicate with a representative image shown. Source data are provided as a Source Data file.