Structural and functional aspects of the multidrug efflux pump AcrB.
The tripartite efflux system AcrA/AcrB/TolC is the main pump in Escherichia coli for the efflux of multiple antibiotics, dyes, bile salts and detergents. The inner membrane component AcrB is central to substrate recognition and energy transduction and acts as a proton/drug antiporter. Recent structural studies show that homotrimeric AcrB can adopt different monomer conformations representing consecutive states in an allosteric functional rotation transport cycle. The conformational changes create an alternate access drug transport tunnel including a hydrophobic substrate binding pocket in one of the cycle intermediates.
Eicher
Thomas
T
Institute of Physiology and Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Winterthurerstrasse 190, CH-8057 Zurich, Switzerland.
Brandstätter
Lorenz
L
Pos
Klaas M
KM
D024901:Drug Resistance, Multiple, Bacterial; D029968:Escherichia coli Proteins / Q000737:chemistry*; D008958:Models, Molecular; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000737:chemistry*; D013379:Substrate Specificity
D029968:Escherichia coli Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C083496:AcrB protein, E coli