PMID: 18073115 , Related PDB id: 2RDD

Authors:

Tornroth-Horsefield S, Gourdon P, Horsefield R, Brive L, Yamamoto N, Mori H, Snijder A, Neutze R

Title:

Crystal structure of AcrB in complex with a single transmembrane subunit reveals another twist.

Journal:

Structure. 2007 Dec;15(12):1663-73.

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.