Extended Data Fig. 3: Tolerance to PmB is not associated with modifications to lipid A.

a, From top to bottom, representative mass spectra showing unmodified lipid A from stationary phase E. coli at time 0 min in MM, stationary phase E. coli at time 15 min in MM, and stationary phase E. coli at time 15 min in MM + G, and stationary phase E. coli at time 15 min in MM + G exposed to 4 µg mL⁻¹ PmB. The peak at ~1800 m/z corresponds to native hexa-acyl diphosphoryl lipid A containing four C14:0 3-OH, one C14:0 and one C12:0¹⁰⁰. The peaks at ~1710 and ~1800 m/z correspond to the subtraction or addition of phosphate to the native form of lipid A. b, Overlaid mass spectra of stationary phase E. coli at time 15 min in MM + G (black) and stationary phase E. coli at time 15 min in MM + G exposed to 4 µg mL⁻¹ PmB (red), indicating a substantial reduction in native lipid A.