2V4D

Re-refinement of MexA adaptor protein


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.20 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.239 
  • R-Value Observed: 0.240 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

The Assembled Structure of a Complete Tripartite Bacterial Multidrug Efflux Pump.

Symmons, M.F.Bokma, E.Koronakis, E.Hughes, C.Koronakis, V.

(2009) Proc Natl Acad Sci U S A 106: 7173

  • DOI: 10.1073/pnas.0900693106
  • Primary Citation of Related Structures:  
    2V4D

  • PubMed Abstract: 
  • Bacteria like Escherichia coli and Pseudomonas aeruginosa expel drugs via tripartite multidrug efflux pumps spanning both inner and outer membranes and the intervening periplasm. In these pumps a periplasmic adaptor protein connects a substrate-binding inner membrane transporter to an outer membrane-anchored TolC-type exit duct ...

    Bacteria like Escherichia coli and Pseudomonas aeruginosa expel drugs via tripartite multidrug efflux pumps spanning both inner and outer membranes and the intervening periplasm. In these pumps a periplasmic adaptor protein connects a substrate-binding inner membrane transporter to an outer membrane-anchored TolC-type exit duct. High-resolution structures of all 3 components are available, but a pump model has been precluded by the incomplete adaptor structure, because of the apparent disorder of its N and C termini. We reveal that the adaptor termini assemble a beta-roll structure forming the final domain adjacent to the inner membrane. The completed structure enabled in vivo cross-linking to map intermolecular contacts between the adaptor AcrA and the transporter AcrB, defining a periplasmic interface between several transporter subdomains and the contiguous beta-roll, beta-barrel, and lipoyl domains of the adaptor. With short and long cross-links expressed as distance restraints, the flexible linear topology of the adaptor allowed a multidomain docking approach to model the transporter-adaptor complex, revealing that the adaptor docks to a transporter region of comparative stability distinct from those key to the proposed rotatory pump mechanism, putative drug-binding pockets, and the binding site of inhibitory DARPins. Finally, we combined this docking with our previous resolution of the AcrA hairpin-TolC interaction to develop a model of the assembled tripartite complex, satisfying all of the experimentally-derived distance constraints. This AcrA(3)-AcrB(3)-TolC(3) model presents a 610,000-Da, 270-A-long efflux pump crossing the entire bacterial cell envelope.


    Organizational Affiliation

    Department of Pathology, Cambridge University, Tennis Court Road, Cambridge CB2 1QP, United Kingdom.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
MULTIDRUG RESISTANCE PROTEIN MEXA
A, B, C, D, E, F, G, H
A, B, C, D, E, F, G, H, I, J, K, L, M
360Pseudomonas aeruginosaMutation(s): 1 
UniProt
Find proteins for P52477 (Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1))
Explore P52477 
Go to UniProtKB:  P52477
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.20 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.239 
  • R-Value Observed: 0.240 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 130.551α = 90
b = 183.585β = 107.38
c = 213.314γ = 90
Software Package:
Software NamePurpose
PHENIXrefinement
MOSFLMdata reduction
SCALAdata scaling
DMphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-04-14
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance