Fig. 2 (IMAGE) Osaka University Caption Evaluation of the putative structures of MexB mutants and the inhibitory effect of ABI-PP on the growth of E. coli expressing MexB mutants. (Top panels) Modeled closeup views of the inhibitor binding pit of ABI-PP-bound MexB mutants I277W, V612W, A279W, V139W, and V571W. The solvent accessible surface is depicted for each mutant, with the exception of mutated tryptophan side chains: in each instance these are depicted as white, space-filling models. ABI-PP is shown as a stick model.. The carbon atoms of ABI-PP are indicated in Cyan. (Bottom Panels) The inhibitory effect of ABI-PP on the growth of E. coli expressing each MexB mutant. The vertical axis represents the turbidity of the culture medium, while the horizontal axis represents the incubation time. Colored lines represent the degree of growth of each mutant pump-expressing strain in the presence of the antibiotic erythromycin and one of several concentrations of PP (inhibitor ABI-PP). If the inhibitor can bind, increases in the inhibitor concentration result in corresponding degrees of inhibition of the pump, preventing antibiotic efflux and reducing bacterial growth (red arrows). Credit 2022 Yamasaki et al., Spatial Characteristics of the Efflux Pump MexB Determine Inhibitor Binding, Antimicrobial Agents and Chemotherapy Usage Restrictions Credit must be given to the creator. License CC BY Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.