Crystal Structure of the Escherichia coli Common Pilus Chaperone, EcpB

Experimental Data Snapshot

  • Resolution: 2.40 Å
  • R-Value Free: 0.238 
  • R-Value Work: 0.205 
  • R-Value Observed: 0.207 

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Structural Insight into Archaic and Alternative Chaperone-Usher Pathways Reveals a Novel Mechanism of Pilus Biogenesis.

Pakharukova, N.Garnett, J.A.Tuittila, M.Paavilainen, S.Diallo, M.Xu, Y.Matthews, S.J.Zavialov, A.V.

(2015) PLoS Pathog 11: e1005269-e1005269

  • DOI: https://doi.org/10.1371/journal.ppat.1005269
  • Primary Citation of Related Structures:  
    5D6H, 5DFK

  • PubMed Abstract: 

    Gram-negative pathogens express fibrous adhesive organelles that mediate targeting to sites of infection. The major class of these organelles is assembled via the classical, alternative and archaic chaperone-usher pathways. Although non-classical systems share a wider phylogenetic distribution and are associated with a range of diseases, little is known about their assembly mechanisms. Here we report atomic-resolution insight into the structure and biogenesis of Acinetobacter baumannii Csu and Escherichia coli ECP biofilm-mediating pili. We show that the two non-classical systems are structurally related, but their assembly mechanism is strikingly different from the classical assembly pathway. Non-classical chaperones, unlike their classical counterparts, maintain subunits in a substantially disordered conformational state, akin to a molten globule. This is achieved by a unique binding mechanism involving the register-shifted donor strand complementation and a different subunit carboxylate anchor. The subunit lacks the classical pre-folded initiation site for donor strand exchange, suggesting that recognition of its exposed hydrophobic core starts the assembly process and provides fresh inspiration for the design of inhibitors targeting chaperone-usher systems.

  • Organizational Affiliation

    Department of Chemistry, University of Turku, Turku, JBL, Arcanum, Turku, Finland.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Probable fimbrial chaperone EcpB217Escherichia coliMutation(s): 0 
Gene Names: ecpBmatCECS88_0289
Find proteins for P77188 (Escherichia coli (strain K12))
Explore P77188 
Go to UniProtKB:  P77188
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP77188
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.40 Å
  • R-Value Free: 0.238 
  • R-Value Work: 0.205 
  • R-Value Observed: 0.207 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 62.65α = 90
b = 62.65β = 90
c = 121.14γ = 120
Software Package:
Software NamePurpose
XDSdata reduction
SCALAdata scaling

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2015-11-04
    Type: Initial release
  • Version 1.1: 2015-12-02
    Changes: Database references