Transport of lipophilic carboxylates is mediated by transmembrane helix 2 in multidrug transporter AcrB

Abstract

The AcrB module of the AcrAB-TolC multidrug efflux pump sequesters drugs from the periplasm and outer leaflet of the inner membrane. Here, Oswaldet al. provide evidence that lipophilic carboxylated substrates bind to a groove between transmembrane helices TM1 and TM2, for further transport by an upward movement of TM2.