10.3390/ijms22105328 MexAB-OprM Efflux Pump Interaction with the Peptidoglycan of Escherichia coli and Pseudomonas aeruginosa Ma Miao Dr. Laboratoire CiTCoM, Université de Paris, CNRS, 75006 Paris, France Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK mm2303@cam.ac.uk Lustig Margaux Dr. Laboratoire CiTCoM, Université de Paris, CNRS, 75006 Paris, France margaux.lustig@parisdescartes.fr Salem Michèle Dr. Laboratoire CiTCoM, Université de Paris, CNRS, 75006 Paris, France michele.salem@u-paris.fr http://orcid.org/0000-0003-3205-0275 Mengin-Lecreulx Dominique Dr. Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France dominique.mengin-lecreulx@i2bc.paris-saclay.fr http://orcid.org/0000-0001-9683-4453 Phan Gilles Dr. Laboratoire CiTCoM, Université de Paris, CNRS, 75006 Paris, France gilles.phan@u-paris.fr http://orcid.org/0000-0001-9862-1232 Broutin Isabelle Dr. Laboratoire CiTCoM, Université de Paris, CNRS, 75006 Paris, France isabelle.broutin@u-paris.fr 18 05 2021 22 10 12 05 2021 e5328 One of the major families of membrane proteins found in prokaryote genome corresponds to the transporters. Among them, the resistance-nodulation-cell division (RND) transporters are highly studied, as being responsible for one of the most problematic mechanisms used by bacteria to resist to antibiotics, i.e., the active efflux of drugs. In Gram-negative bacteria, these proteins are inserted in the inner membrane and form a tripartite assembly with an outer membrane factor and a periplasmic linker in order to cross the two membranes to expulse molecules outside of the cell. A lot of information has been collected to understand the functional mechanism of these pumps, especially with AcrAB-TolC from Escherichia coli, but one missing piece from all the suggested models is the role of peptidoglycan in the assembly. Here, by pull-down experiments with purified peptidoglycans, we precise the MexAB-OprM interaction with the peptidoglycan from Escherichia coli and Pseudomonas aeruginosa, highlighting a role of the peptidoglycan in stabilizing the MexA-OprM complex and also differences between the two Gram-negative bacteria peptidoglycans. Agence Nationale de la Recherche ANR-12-BSV8-0010 ANR-17-CE11-0028-02 © 1996-2021 MDPI (Basel, Switzerland) 2021 This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited membrane peptidoglycan efflux pump assembly resistance Pseudomonas International Journal of Molecular Sciences Int J Mol Sci 1422-0067 MDPI