title: Cross-linked complex between oligomeric periplasmic lipoprotein AcrA and the inner-membrane-associated multidrug efflux pump AcrB from Escherichia coli.
abstract: In Escherichia coli, the intrinsic levels of resistance to multiple antimicrobial agents are produced through expression of the three-component multidrug efflux system AcrAB-TolC. AcrB is a proton-motive-force-dependent transporter located in the inner membrane, and AcrA and TolC are accessory proteins located in the periplasm and the outer membrane, respectively. In this study, these three proteins were expressed separately, and the interactions between them were analyzed by chemical cross-linking in intact cells. We show that AcrA protein forms oligomers, most probably trimers. In this oligomeric form, AcrA interacts specifically with AcrB transporter independently of substrate and TolC.
authors.affiliation: Department of Molecular and Cell Biology, University of California, Berkeley, California 94720-3206, USA.
authors.forename: H I
authors.initials: HI
authors.lastname: Zgurskaya
authors.forename: H
authors.initials: H
authors.lastname: Nikaido
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D002352:Carrier Proteins; D004352:Drug Resistance, Microbial; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins; D008074:Lipoproteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D026901:Membrane Transport Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D011485:Protein Binding; D017433:Protein Structure, Secondary
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D008074:Lipoproteins; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C083497:AcrA protein, E coli; C083496:AcrB protein, E coli