2V50 image
Deposition Date 2008-10-01
Release Date 2009-05-19
Last Version Date 2023-12-13
Entry Detail
PDB ID:
2V50
Title:
The Missing Part of the Bacterial MexAB-OprM System: Structural determination of the Multidrug Exporter MexB
Biological Source:
Source Organism:
Method Details:
Experimental Method:
Resolution:
3.00 Å
R-Value Free:
0.28
R-Value Work:
0.24
R-Value Observed:
0.24
Space Group:
P 1
Macromolecular Entities
Polymer Type:polypeptide(L)
Molecule:MULTIDRUG RESISTANCE PROTEIN MEXB
Gene (Uniprot):mexB
Chain IDs:A, B, C, D, E, F
Chain Length:1052
Number of Molecules:6
Biological Source:PSEUDOMONAS AERUGINOSA PA01
Ligand Molecules
Primary Citation
Crystal Structure of the Multidrug Exporter Mexb from Pseudomonas Aeruginosa.
J.Mol.Biol. 389 134 ? (2009)
PMID: 19361527 DOI: 10.1016/J.JMB.2009.04.001

Abstact

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.

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Primary Citation of related structures