AcrAB and related multidrug efflux pumps of Escherichia coli

J Mol Microbiol Biotechnol. 2001 Apr;3(2):215-8.


The AcrAB system of Escherichia coli is a multidrug efflux system composed of an RND-type transporter AcrB and a periplasmic accessory protein AcrA, and pumps out a wide variety of lipophilic and amphiphilic inhibitors directly into the medium, presumably through the TolC outer membrane channel. AcrA, a highly elongated protein, is thought to bring the outer and inner membranes closer. It forms a trimer that interacts with a monomeric AcrB, which was shown by in vitro reconstitution to be a proton antiporter. Details of interaction between the

Publication types

  • Research Support, U.S. Gov't, P.H.S.
  • Review

MeSH terms

  • Bacterial Outer Membrane Proteins / chemistry
  • Bacterial Outer Membrane Proteins / metabolism
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / metabolism*
  • Binding Sites
  • Carrier Proteins / metabolism
  • Drug Resistance, Microbial*
  • Drug Resistance, Multiple*
  • Escherichia coli / genetics
  • Escherichia coli / physiology*
  • Escherichia coli Proteins*
  • Lipoproteins / chemistry
  • Lipoproteins / metabolism*
  • Membrane Proteins / chemistry
  • Membrane Proteins / metabolism*
  • Membrane Transport Proteins
  • Models, Molecular
  • Multidrug Resistance-Associated Proteins
  • Protein Structure, Secondary


  • AcrA protein, E coli
  • AcrB protein, E coli
  • Bacterial Outer Membrane Proteins
  • Bacterial Proteins
  • Carrier Proteins
  • Escherichia coli Proteins
  • Lipoproteins
  • Membrane Proteins
  • Membrane Transport Proteins
  • Multidrug Resistance-Associated Proteins
  • tolC protein, E coli