Extended Data Fig. 1: Evaluation of the biochemical activity of MsbA and inhibitors.

a, Quinoline inhibitors described in this study. b, Comparison of ATPase activity of increasing concentrations of E. coli MsbA in amphipol, nanodisc and FA-3 detergent matrices. c, d, Dose–response curves of compounds on purified Klebsiella pneumoniae (c) and Pseudomonas aeruginosa (d) MsbA reconstituted in amphipols. e, f, Dose–response curves of compounds on purified E. coli MsbA reconstituted in nanodiscs (e) or FA-3 detergent (f). g, h, Dose–response curves of compounds on purified E. coli A175V mutant MsbA reconstituted in amphipols (g) and nanodiscs (h). i, The LPS content of purified E. coli MsbA in the indicated matrices was measured using a chromogenic endotoxin quantitation assay (see Methods section ‘Quantitation of co-purifying LPS’). LPS from E. coli strain O111:B4 was used to generate a standard curve. Note that for both MsbA samples (0.0024 ng ml⁻¹), the concentration of LPS (more than 0.02 ng ml⁻¹) exceeds the concentration of MsbA, indicating a molar excess of co-purifying LPS. Data are mean ± s.e.m. from five independent experiments (b), three independent experiments (c–h) or two independent experiments (i). IC₅₀ values (b–h, in parentheses) were determined by fitting the inhibition dose–response curve with a nonlinear four-parameter inhibition model (see Methods section ‘MsbA ATPase assay’).

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