7NG9

Trimeric efflux pump Klebsiella TolC


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.30 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 

Starting Model: experimental
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wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Toxin import through the antibiotic efflux channel TolC.

Housden, N.G.Webby, M.N.Lowe, E.D.El-Baba, T.J.Kaminska, R.Redfield, C.Robinson, C.V.Kleanthous, C.

(2021) Nat Commun 12: 4625-4625

  • DOI: https://doi.org/10.1038/s41467-021-24930-y
  • Primary Citation of Related Structures:  
    7NG8, 7NG9, 7NNA

  • PubMed Abstract: 

    Bacteria often secrete diffusible protein toxins (bacteriocins) to kill bystander cells during interbacterial competition. Here, we use biochemical, biophysical and structural analyses to show how a bacteriocin exploits TolC, a major outer-membrane antibiotic efflux channel in Gram-negative bacteria, to transport itself across the outer membrane of target cells. Klebicin C (KlebC), a rRNase toxin produced by Klebsiella pneumoniae, binds TolC of a related species (K. quasipneumoniae) with high affinity through an N-terminal, elongated helical hairpin domain common amongst bacteriocins. The KlebC helical hairpin opens like a switchblade to bind TolC. A cryo-EM structure of this partially translocated state, at 3.1 Å resolution, reveals that KlebC associates along the length of the TolC channel. Thereafter, the unstructured N-terminus of KlebC protrudes beyond the TolC iris, presenting a TonB-box sequence to the periplasm. Association with proton-motive force-linked TonB in the inner membrane drives toxin import through the channel. Finally, we demonstrate that KlebC binding to TolC blocks drug efflux from bacteria. Our results indicate that TolC, in addition to its known role in antibiotic export, can function as a protein import channel for bacteriocins.


  • Organizational Affiliation

    Department of Biochemistry, University of Oxford, Oxford, UK.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Outer membrane channel protein
A, B, C
494Klebsiella quasipneumoniaeMutation(s): 0 
Gene Names: tolCCP911_05930DBL00_17640G5630_14450SAMEA104168726_00630SAMEA3531848_02756
Membrane Entity: Yes 
UniProt
Find proteins for A0A1C3Q001 (Klebsiella quasipneumoniae)
Explore A0A1C3Q001 
Go to UniProtKB:  A0A1C3Q001
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupA0A1C3Q001
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 3.30 Å
  • Aggregation State: PARTICLE 
  • Reconstruction Method: SINGLE PARTICLE 
EM Software:
TaskSoftware PackageVersion
MODEL REFINEMENTPHENIX
RECONSTRUCTIONRELION

Structure Validation

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Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
Wellcome Trust--

Revision History  (Full details and data files)

  • Version 1.0: 2021-06-30
    Type: Initial release
  • Version 1.1: 2021-10-13
    Changes: Data collection, Database references
  • Version 1.2: 2024-07-10
    Changes: Data collection, Refinement description