Fig. 5: The T434A mutation has an impact on BamA’s function, leading to an altered outer membrane.

a The T434A mutation on BamA decreases the effect of darobactin B on the folding activity of BAM in an in vitro folding assay. Quantification of the folded fraction of tOmpA against time, from the SDS-PAGE band-shift assay. The folded fraction values calculated from two technical repeats are shown, and dashed lines represent a single exponential fit to the data. b, c Cells expressing a BamA variant with the T434A point-mutation have outer membrane defects. bamA::kan cells expressing variants of BamA from a plasmid were grown in LB medium at 37 °C until mid-log phase. b Cells were spotted on a gradient plate containing a fixed concentration of SDS (0.5% (w/v)) and a gradient of EDTA (0–0.4 mM) (top) and incubated overnight at 37 °C. For the deoxycholate (DOC) 1% (w/v) plate (bottom), ten-fold serial dilutions were made in LB and spotted onto the plate, and the plates were incubated at 30 °C. c Ten-fold serial dilutions were made in LB medium and plated on LB agar plates (top) or plates containing 15 μg/mL of vancomycin (bottom). Plates were incubated for 5 days at 15 °C.