6NRV

Cryo-EM reconstruction of CFA/I pili


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 4 Å
  • Aggregation State: FILAMENT 
  • Reconstruction Method: HELICAL 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Cryo-EM structure of the CFA/I pilus rod.

Zheng, W.Andersson, M.Mortezaei, N.Bullitt, E.Egelman, E.

(2019) Iucrj 6: 815-821

  • DOI: 10.1107/S2052252519007966

  • PubMed Abstract: 
  • Enterotoxigenic <i>Escherichia coli </i> (ETEC) are common agents of diarrhea for travelers and a major cause of mortality in children in developing countries. To attach to intestinal cells ETEC express colonization factors, among them CFA/I, which ...

    Enterotoxigenic Escherichia coli (ETEC) are common agents of diarrhea for travelers and a major cause of mortality in children in developing countries. To attach to intestinal cells ETEC express colonization factors, among them CFA/I, which are the most prevalent factors and are the archetypical representative of class 5 pili. The helical quaternary structure of CFA/I can be unwound under tensile force and it has been shown that this mechanical property helps bacteria to withstand shear forces from fluid motion. We report in this work the CFA/I pilus structure at 4.3 Å resolution from electron cryomicroscopy (cryo-EM) data, and report details of the donor strand complementation. The CfaB pilins modeled into the cryo-EM map allow us to identify the buried surface area between subunits, and these regions are correlated to quaternary structural stability in class 5 and chaperone-usher pili. In addition, from the model built using the EM structure we also predicted that residue 13 (proline) of the N-terminal β-strand could have a major impact on the filament's structural stability. Therefore, we used optical tweezers to measure and compare the stability of the quaternary structure of wild type CFA/I and a point-mutated CFA/I with a propensity for unwinding. We found that pili with this mutated CFA/I require a lower force to unwind, supporting our hypothesis that Pro13 is important for structural stability. The high-resolution CFA/I pilus structure presented in this work and the analysis of structural stability will be useful for the development of novel antimicrobial drugs that target adhesion pili needed for initial attachment and sustained adhesion of ETEC.


    Organizational Affiliation

    Department of Physics, Umeå University, Umeå, Sweden.,Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA, USA.,Physiology and Biophysics, Boston University School of Medicine, 700 Albany Street, Boston, MA 02118, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
CFA/I fimbrial subunit B
A, B, C, D, E, F, G, H, I, J, K, L, M
146Escherichia coliMutation(s): 0 
Gene Names: cfaB
Find proteins for P0CK93 (Escherichia coli)
Go to UniProtKB:  P0CK93
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 4 Å
  • Aggregation State: FILAMENT 
  • Reconstruction Method: HELICAL 
Software Package:
Software NamePurpose
PHENIXrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)United StatesR35GM122510

Revision History 

  • Version 1.0: 2019-09-11
    Type: Initial release
  • Version 1.1: 2019-11-13
    Type: Database references
  • Version 1.2: 2020-01-08
    Type: Author supporting evidence