2V50

The Missing Part of the Bacterial MexAB-OprM System: Structural determination of the Multidrug Exporter MexB

Summary for 2V50

• Entry DOI: 10.2210/pdb2v50/pdb
• Descriptor: MULTIDRUG RESISTANCE PROTEIN MEXB, DODECYL-BETA-D-MALTOSIDE (2 entities in total)
• Functional Keywords: multidrug resistance protein, ddm, rnd, membrane, detergent, transport, cell membrane, transmembrane, membrane protein, cell inner membrane, antibiotic resistance, drug-efflux pump, transport protein
• Biological source: PSEUDOMONAS AERUGINOSA PA01
• Cellular location: Cell inner membrane; Multi-pass membrane protein: P52002
• Total number of polymer chains: 6
• Total formula weight: 686320.97

Authors

Sennhauser, G.,Bukowska, M.A.,Gruetter, M.G. (deposition date: 2008-10-01, release date: 2009-05-19, Last modification date: 2023-12-13)

Primary citation

Sennhauser, G.,Bukowska, M.A.,Briand, C.,Gruetter, M.G.
Crystal Structure of the Multidrug Exporter Mexb from Pseudomonas Aeruginosa.
J.Mol.Biol., 389:134-, 2009

PubMed Abstract: We report here the crystal structure of the Pseudomonas aeruginosa multidrug exporter MexB, an intensively studied member of the resistance-nodulation-cell division family of secondary active transporters, at 3.0 A. MexB forms an asymmetric homotrimer where each subunit adopts a different conformation representing three snapshots of the transport cycle similar to the recently determined structures of its close homologue AcrB from Escherichia coli, so far the sole structurally characterized member of the superfamily. As for AcrB, the conformations of two subunits can be clearly assigned to either the binding step or the extrusion step in the transport process. Unexpectedly, a remarkable conformational shift in the third subunit is observed in MexB, which has potential implications for the assembly of the tripartite MexAB-OprM drug efflux system. Furthermore, an n-dodecyl-d-maltoside molecule was found bound to the internal multidrug-binding cavity, which might indicate that MexB binds and transports detergent molecules as substrates. As the only missing piece of the puzzle in the MexAB-OprM system, the X-ray structure of MexB completes the molecular picture of the major pump mediating intrinsic and acquired multidrug resistance in P. aeruginosa.

PubMed: 19361527
DOI: 10.1016/J.JMB.2009.04.001

Experimental method

X-RAY DIFFRACTION (3 Å)