3G20

Crystal structure of the major pseudopilin from the type 2 secretion system of enterohaemorrhagic Escherichia coli


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.78 Å
  • R-Value Free: 0.222 
  • R-Value Work: 0.168 
  • R-Value Observed: 0.170 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Calcium is essential for the major pseudopilin in the type 2 secretion system.

Korotkov, K.V.Gray, M.D.Kreger, A.Turley, S.Sandkvist, M.Hol, W.G.

(2009) J Biol Chem 284: 25466-25470

  • DOI: 10.1074/jbc.C109.037655
  • Primary Citation of Related Structures:  
    3FU1, 3G20, 3GN9

  • PubMed Abstract: 
  • The pseudopilus is a key feature of the type 2 secretion system (T2SS) and is made up of multiple pseudopilins that are similar in fold to the type 4 pilins. However, pilins have disulfide bridges, whereas the major pseudopilins of T2SS do not. A key question is therefore how the pseudopilins, and in particular, the most abundant major pseudopilin, GspG, obtain sufficient stability to perform their function ...

    The pseudopilus is a key feature of the type 2 secretion system (T2SS) and is made up of multiple pseudopilins that are similar in fold to the type 4 pilins. However, pilins have disulfide bridges, whereas the major pseudopilins of T2SS do not. A key question is therefore how the pseudopilins, and in particular, the most abundant major pseudopilin, GspG, obtain sufficient stability to perform their function. Crystal structures of Vibrio cholerae, Vibrio vulnificus, and enterohemorrhagic Escherichia coli (EHEC) GspG were elucidated, and all show a calcium ion bound at the same site. Conservation of the calcium ligands fully supports the suggestion that calcium ion binding by the major pseudopilin is essential for the T2SS. Functional studies of GspG with mutated calcium ion-coordinating ligands were performed to investigate this hypothesis and show that in vivo protease secretion by the T2SS is severely impaired. Taking all evidence together, this allows the conclusion that, in complete contrast to the situation in the type 4 pili system homologs, in the T2SS, the major protein component of the central pseudopilus is dependent on calcium ions for activity.


    Organizational Affiliation

    Department of Biochemistry, Biomolecular Structure Center, University of Washington, Seattle, Washington 98195, USA.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Type II secretion proteinA, B123Escherichia coli O157:H7Mutation(s): 0 
Gene Names: ECO57PM05etpGGSPGL7036
UniProt
Find proteins for Q7BSV8 (Escherichia coli O157:H7)
Explore Q7BSV8 
Go to UniProtKB:  Q7BSV8
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ7BSV8
Protein Feature View
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  • Reference Sequence
Small Molecules
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.78 Å
  • R-Value Free: 0.222 
  • R-Value Work: 0.168 
  • R-Value Observed: 0.170 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 26.12α = 106.94
b = 36.83β = 99.05
c = 61.27γ = 90.17
Software Package:
Software NamePurpose
XSCALEdata scaling
PHASERphasing
REFMACrefinement
PDB_EXTRACTdata extraction
Blu-Icedata collection
XDSdata reduction

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-07-28
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Advisory, Version format compliance
  • Version 1.2: 2017-11-01
    Changes: Refinement description