title: Crystal structure of AcrB in complex with a single transmembrane subunit reveals another twist.
abstract: Bacterial drug resistance is a serious concern for human health. Multidrug efflux pumps export a broad variety of substrates out of the cell and thereby convey resistance to the host. In Escherichia coli, the AcrB:AcrA:TolC efflux complex forms a principal transporter for which structures of the individual component proteins have been determined in isolation. Here, we present the X-ray structure of AcrB in complex with a single transmembrane protein, assigned by mass spectrometry as YajC. A specific rotation of the periplasmic porter domain of AcrB is also revealed, consistent with the hypothesized "twist-to-open" mechanism for TolC activation. Growth experiments with yajc-deleted E. coli reveal a modest increase in the organism's susceptibility to beta-lactam antibiotics, but this effect could not conclusively be attributed to the loss of interactions between YajC and AcrB.
authors: Department of Chemistry, Biochemistry and Biophysics, Gothenburg University, 40530 Gothenburg, Sweden. susanna.tornroth@chem.gu.se
authors: Susanna
authors: S
authors: Törnroth-Horsefield
authors: Pontus
authors: P
authors: Gourdon
authors: Rob
authors: R
authors: Horsefield
authors: Lars
authors: L
authors: Brive
authors: Natsuko
authors: N
authors: Yamamoto
authors: Hirotada
authors: H
authors: Mori
authors: Arjan
authors: A
authors: Snijder
authors: Richard
authors: R
authors: Neutze
mesh_terms: D029968:Escherichia coli Proteins / Q000737:chemistry*; D008958:Models, Molecular; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000737:chemistry*; D011487:Protein Conformation; D017550:Spectroscopy, Fourier Transform Infrared; D053719:Tandem Mass Spectrometry; D014961:X-Ray Diffraction
chemical_list: D029968:Escherichia coli Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C083496:AcrB protein, E coli