Methylated Shigella flexneri MxiC

Experimental Data Snapshot

  • Resolution: 2.50 Å
  • R-Value Free: 0.265 
  • R-Value Work: 0.211 
  • R-Value Observed: 0.211 

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This is version 1.3 of the entry. See complete history


Structures of the Shigella Flexneri Type 3 Secretion System Protein Mxic Reveal Conformational Variability Amongst Homologues.

Deane, J.E.Roversi, P.King, C.Johnson, S.Lea, S.M.

(2008) J Mol Biol 377: 985

  • DOI: https://doi.org/10.1016/j.jmb.2008.01.072
  • Primary Citation of Related Structures:  
    2VIX, 2VJ4, 2VJ5

  • PubMed Abstract: 

    Many Gram-negative pathogenic bacteria use a complex macromolecular machine, known as the type 3 secretion system (T3SS), to transfer virulence proteins into host cells. The T3SS is composed of a cytoplasmic bulb, a basal body spanning the inner and outer bacterial membranes, and an extracellular needle. Secretion is regulated by both cytoplasmic and inner membrane proteins that must respond to specific signals in order to ensure that virulence proteins are not secreted before contact with a eukaryotic cell. This negative regulation is mediated, in part, by a family of proteins that are thought to physically block the entrance to the secretion apparatus until an appropriate signal is received following host cell contact. Despite weak sequence homology between proteins of this family, the crystal structures of Shigella flexneri MxiC we present here confirm the conservation of domain topology with the homologue from Yersinia sp. Interestingly, comparison of the Shigella and Yersinia structures reveals a significant structural change that results in substantial domain re-arrangement and opening of one face of the molecule. The conservation of a negatively charged patch on this face suggests it may have a role in binding other components of the T3SS.

  • Organizational Affiliation

    Sir William Dunn School of Pathology, South Parks Rd, University of Oxford, Oxford OX1 3RE, UK.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
294Shigella flexneriMutation(s): 0 
Find proteins for Q04640 (Shigella flexneri)
Explore Q04640 
Go to UniProtKB:  Q04640
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ04640
Sequence Annotations
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
Query on MLY
A, B
Experimental Data & Validation

Experimental Data

  • Resolution: 2.50 Å
  • R-Value Free: 0.265 
  • R-Value Work: 0.211 
  • R-Value Observed: 0.211 
  • Space Group: P 2 2 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 83.48α = 90
b = 83.45β = 90
c = 117.07γ = 90
Software Package:
Software NamePurpose
MOSFLMdata reduction
SCALAdata scaling

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2008-03-11
    Type: Initial release
  • Version 1.1: 2011-05-08
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-12-13
    Changes: Data collection, Database references, Derived calculations, Other, Refinement description