Conformational Flexibility in the Multidrug Efflux System Protein AcrA

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...

High-level fluoroquinolone-resistant clinical isolates of Escherichia coli overproduce multidrug efflux protein AcrA.

Immunoblotting with antibody against AcrA, an obligatory component of the AcrAB multidrug efflux system, showed that this protein was overexpressed by >/=170% in 9 of 10 clinical isolates of Esherichia coli with high-level ciprofloxacin resistance (MICs, >/=32 microg/ml) but not in any of the 15 isolates for which the MIC was </=1 microg/ml.

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...

Redundancy in the periplasmic adaptor proteins AcrA and AcrE provides resilience and an ability to export substrates of multidrug efflux.

OBJECTIVES The components of the AcrAB-TolC efflux pump function as a tripartite efflux system conferring resistance to multiple antibiotics and the individual components can also function in conjunction with other efflux pumps. This study aimed to establish whether redundancy exists between the homologous periplasmic adaptor proteins (PAPs) AcrA and AcrE and to measure the impact of this redun...