1EK9

2.1A X-RAY STRUCTURE OF TOLC: AN INTEGRAL OUTER MEMBRANE PROTEIN AND EFFLUX PUMP COMPONENT FROM ESCHERICHIA COLI


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.208 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structure of the bacterial membrane protein TolC central to multidrug efflux and protein export.

Koronakis, V.Sharff, A.Koronakis, E.Luisi, B.Hughes, C.

(2000) Nature 405: 914-919

  • DOI: 10.1038/35016007

  • PubMed Abstract: 
  • Diverse molecules, from small antibacterial drugs to large protein toxins, are exported directly across both cell membranes of gram-negative bacteria. This export is brought about by the reversible interaction of substrate-specific inner-membrane pro ...

    Diverse molecules, from small antibacterial drugs to large protein toxins, are exported directly across both cell membranes of gram-negative bacteria. This export is brought about by the reversible interaction of substrate-specific inner-membrane proteins with an outer-membrane protein of the TolC family, thus bypassing the intervening periplasm. Here we report the 2.1-A crystal structure of TolC from Escherichia coli, revealing a distinctive and previously unknown fold. Three TolC protomers assemble to form a continuous, solvent-accessible conduit--a 'channel-tunnel' over 140 A long that spans both the outer membrane and periplasmic space. The periplasmic or proximal end of the tunnel is sealed by sets of coiled helices. We suggest these could be untwisted by an allosteric mechanism, mediated by protein-protein interactions, to open the tunnel. The structure provides an explanation of how the cell cytosol is connected to the external environment during export, and suggests a general mechanism for the action of bacterial efflux pumps.


    Related Citations: 
    • Oxidation of Selenomethionine: Some MADness in the Method!
      Sharff, A.J.,Koronakis, E.,Luisi, B.,Koronakis, V.
      (2000) Acta Crystallogr.,Sect.D 56: 785


    Organizational Affiliation

    Department of Pathology, University of Cambridge, UK.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
OUTER MEMBRANE PROTEIN TOLC
A, B, C
428Escherichia coli (strain K12)Mutation(s): 0 
Gene Names: tolC (colE1-i, mtcB, mukA, refI, toc, weeA)
Membrane protein
mpstruct
Group: 
TRANSMEMBRANE PROTEINS: BETA-BARREL
Sub Group: 
Beta-Barrel Membrane Proteins: Monomeric/Dimeric
Protein: 
TolC outer membrane protein
Find proteins for P02930 (Escherichia coli (strain K12))
Go to UniProtKB:  P02930
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A, B, C
L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.1 Å
  • R-Value Free: 0.257 
  • R-Value Work: 0.208 
  • Space Group: H 3
Unit Cell:
Length (Å)Angle (°)
a = 265.049α = 90.00
b = 265.049β = 90.00
c = 95.959γ = 120.00
Software Package:
Software NamePurpose
DENZOdata reduction
SCALEPACKdata scaling
SHARPphasing
BUSTER-TNTrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2000-06-28
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance