Flexibility of Free and AcrB-Bound AcrA in the AcrAB-TolC Multidrug Efflux Pump of Escherichia coli Determined using 3D PMFS

AcrA, AcrB, and TolC of Escherichia coli Form a Stable Intermembrane Multidrug Efflux Complex.

Many transporters of Gram-negative bacteria involved in the extracellular secretion of proteins and the efflux of toxic molecules operate by forming intermembrane complexes. These complexes are proposed to span both inner and outer membranes and create a bridge across the periplasm. In this study, we analyzed interactions between the inner and outer membrane components of the tri-partite multid...

Pimozide Inhibits the AcrAB-TolC Efflux Pump in Escherichia coli

Efflux pump inhibitors (EPIs) are attractive compounds to reverse multidrug-resistance in clinically relevant bacterial pathogens. In this study we tested the ability of the neuroleptic drug pimozide to inhibit the Escherichia coli AcrAB-TolC efflux pump, whose overproduction confers resistance to various antimicrobial agents. A real-time Nile red efflux assay in the AcrAB - overproducing strai...

Escherichia coli Proteins of a Multidrug Efflux System of Interaction between the TolC and AcrA

Interaction between the TolC and AcrA proteins of a multidrug efflux system of Escherichia coli.

This paper provides the biochemical evidence for physical interactions between the outer membrane component, TolC, and the membrane fusion protein component, AcrA, of the major antibiotic efflux pump of Escherichia coli. Cross-linking between TolC and AcrA was independent of the presence of any externally added substrate of the efflux pump or of the pump protein, AcrB. The biochemical demonstra...

Evidence that TolC is required for functioning of the Mar/AcrAB efflux pump of Escherichia coli.

A study examining the influence of TolC on AcrA, AcrR, and MarR1 mutants indicates that functional TolC is required for the operation of the AcrAB efflux system and for the expression of the Mar phenotype. That the effect of TolC on the AcrAB pump is not regulatory in nature is shown by studies measuring the influence of a tolC::Tn10 insertion mutation on the expression of an acrA::lacZ reporte...