The Xenobiotic Extrusion Mechanism of the MATE Transporter NorM_PS from Pseudomonas stutzeri.

Autor: Eisinger ML; Department of Molecular Membrane Biology, Max-Planck-Institute of Biophysics, Frankfurt am Main, Germany., Nie L; Department of Molecular Membrane Biology, Max-Planck-Institute of Biophysics, Frankfurt am Main, Germany. Electronic address: laiyin.nie@sgc.ox.ac.uk., Dörrbaum AR; Department for Synaptic Plasticity, Max-Planck-Institute for Brain Research, Frankfurt am Main, Germany., Langer JD; Department of Molecular Membrane Biology, Max-Planck-Institute of Biophysics, Frankfurt am Main, Germany. Electronic address: julian.langer@biophys.mpg.de., Michel H; Department of Molecular Membrane Biology, Max-Planck-Institute of Biophysics, Frankfurt am Main, Germany. Electronic address: hartmut.michel@biophys.mpg.de.
Jazyk: angličtina
Zdroj: Journal of molecular biology [J Mol Biol] 2018 Apr 27; Vol. 430 (9), pp. 1311-1323. Date of Electronic Publication: 2018 Mar 16.
DOI: 10.1016/j.jmb.2018.03.012
Abstrakt: Multidrug resistance (MDR) in bacterial pathogens has become a severe threat to public health. Membrane transporters of the multidrug and toxic compound extrusion (MATE) family contribute critically to MDR, making them promising drug targets. Despite recent advances, structures in different conformations and the mechanistic details of their antiport cycle are still elusive. Here we studied NorM_PS, a representative MATE transporter from Pseudomonas stutzeri, using biochemical assays in combination with hydrogen/deuterium exchange-mass spectrometry. Our results confirm that the antiport is proton dependent and electroneutral with a stoichiometry of two protons per one doubly positively charged substrate. We investigated the conformational dynamics upon substrate binding, and our hydrogen/deuterium exchange-mass spectrometry analysis revealed an occlusion in the proposed binding site as well as a closure of the cytoplasmic cavity and formation of a periplasmic cavity. Together with the results of selected variants (D38N, D373N and Q376A), we propose a six-step rocker-switch model for NorM_PS, which also increases our understanding of related MATE transporters and may help to fight the burden of MDR.
(Copyright © 2018 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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