title: Tripartite assembly of RND multidrug efflux pumps.
abstract: Tripartite multidrug efflux systems of Gram-negative bacteria are composed of an inner membrane transporter, an outer membrane channel and a periplasmic adaptor protein. They are assumed to form ducts inside the periplasm facilitating drug exit across the outer membrane. Here we present the reconstitution of native Pseudomonas aeruginosa MexAB-OprM and Escherichia coli AcrAB-TolC tripartite Resistance Nodulation and cell Division (RND) efflux systems in a lipid nanodisc system. Single-particle analysis by electron microscopy reveals the inner and outer membrane protein components linked together via the periplasmic adaptor protein. This intrinsic ability of the native components to self-assemble also leads to the formation of a stable interspecies AcrA-MexB-TolC complex suggesting a common mechanism of tripartite assembly. Projection structures of all three complexes emphasize the role of the periplasmic adaptor protein as part of the exit duct with no physical interaction between the inner and outer membrane components.
authors: Université de Bordeaux, CBMN UMR 5248, Bordeaux INP, IECB, Pessac F-33600, France.|CNRS, CBMN UMR 5248, Pessac F-33600, France.
authors: Laetitia
authors: L
authors: Daury
authors: Université de Bordeaux, CBMN UMR 5248, Bordeaux INP, IECB, Pessac F-33600, France.|CNRS, CBMN UMR 5248, Pessac F-33600, France.
authors: François
authors: F
authors: Orange
authors: Université de Bordeaux, CBMN UMR 5248, Bordeaux INP, IECB, Pessac F-33600, France.|CNRS, CBMN UMR 5248, Pessac F-33600, France.
authors: Jean-Christophe
authors: JC
authors: Taveau
authors: Laboratoire de Cristallographie et RMN Biologiques, UMR 8015, CNRS, Université Paris Descartes, Faculté de Pharmacie, 4 Avenue de l'Observatoire, Paris 75006, France.
authors: Alice
authors: A
authors: Verchère
authors: Laboratoire de Cristallographie et RMN Biologiques, UMR 8015, CNRS, Université Paris Descartes, Faculté de Pharmacie, 4 Avenue de l'Observatoire, Paris 75006, France.
authors: Laura
authors: L
authors: Monlezun
authors: Université de Bordeaux, CBMN UMR 5248, Bordeaux INP, IECB, Pessac F-33600, France.|CNRS, CBMN UMR 5248, Pessac F-33600, France.
authors: Céline
authors: C
authors: Gounou
authors: Institute of Biochemistry, Goethe-University Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt am Main, Germany.
authors: Ravi K R
authors: RK
authors: Marreddy
authors: Laboratoire de Cristallographie et RMN Biologiques, UMR 8015, CNRS, Université Paris Descartes, Faculté de Pharmacie, 4 Avenue de l'Observatoire, Paris 75006, France.
authors: Martin
authors: M
authors: Picard
authors: Laboratoire de Cristallographie et RMN Biologiques, UMR 8015, CNRS, Université Paris Descartes, Faculté de Pharmacie, 4 Avenue de l'Observatoire, Paris 75006, France.
authors: Isabelle
authors: I
authors: Broutin
authors: Institute of Biochemistry, Goethe-University Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt am Main, Germany.
authors: Klaas M
authors: KM
authors: Pos
authors: Université de Bordeaux, CBMN UMR 5248, Bordeaux INP, IECB, Pessac F-33600, France.|CNRS, CBMN UMR 5248, Pessac F-33600, France.
authors: Olivier
authors: O
authors: Lambert
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism* / Q000648:ultrastructure; D024901:Drug Resistance, Multiple, Bacterial; D004926:Escherichia coli; D029968:Escherichia coli Proteins / Q000378:metabolism* / Q000648:ultrastructure; D008074:Lipoproteins / Q000378:metabolism* / Q000648:ultrastructure; D026901:Membrane Transport Proteins / Q000378:metabolism* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000378:metabolism* / Q000648:ultrastructure; D046912:Multiprotein Complexes / Q000378:metabolism* / Q000648:ultrastructure; D049329:Nanostructures; D063347:Native Polyacrylamide Gel Electrophoresis; D033903:Periplasmic Proteins / Q000378:metabolism; D011550:Pseudomonas aeruginosa
chemical_list: D001425:Bacterial Outer Membrane Proteins; D029968:Escherichia coli Proteins; D008074:Lipoproteins; D026901:Membrane Transport Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D046912:Multiprotein Complexes; D033903:Periplasmic Proteins; C083497:AcrA protein, E coli; C083496:AcrB protein, E coli; C118598:MexA protein, Pseudomonas aeruginosa; C118597:MexB protein, Pseudomonas aeruginosa; C402263:OprM protein, Pseudomonas aeruginosa; C073126:tolC protein, E coli