4AKX

Structure of the heterodimeric complex ExoU-SpcU from the type III secretion system (T3SS) of Pseudomonas aeruginosa


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.94 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.208 
  • R-Value Observed: 0.211 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

Structural Basis of Cytotoxicity Mediated by the Type III Secretion Toxin Exou from Pseudomonas Aeruginosa

Gendrin, C.Contreras-Martel, C.Bouillot, S.Elsen, S.Lemaire, D.Skoufias, D.A.Huber, P.Attree, I.Dessen, A.

(2012) PLoS Pathog 8: 2637

  • DOI: 10.1371/journal.ppat.1002637
  • Primary Citation of Related Structures:  
    4AKX

  • PubMed Abstract: 
  • The type III secretion system (T3SS) is a complex macromolecular machinery employed by a number of Gram-negative pathogens to inject effectors directly into the cytoplasm of eukaryotic cells. ExoU from the opportunistic pathogen Pseudomonas aeruginosa is one of the most aggressive toxins injected by a T3SS, leading to rapid cell necrosis ...

    The type III secretion system (T3SS) is a complex macromolecular machinery employed by a number of Gram-negative pathogens to inject effectors directly into the cytoplasm of eukaryotic cells. ExoU from the opportunistic pathogen Pseudomonas aeruginosa is one of the most aggressive toxins injected by a T3SS, leading to rapid cell necrosis. Here we report the crystal structure of ExoU in complex with its chaperone, SpcU. ExoU folds into membrane-binding, bridging, and phospholipase domains. SpcU maintains the N-terminus of ExoU in an unfolded state, required for secretion. The phospholipase domain carries an embedded catalytic site whose position within ExoU does not permit direct interaction with the bilayer, which suggests that ExoU must undergo a conformational rearrangement in order to access lipids within the target membrane. The bridging domain connects catalytic domain and membrane-binding domains, the latter of which displays specificity to PI(4,5)P₂. Both transfection experiments and infection of eukaryotic cells with ExoU-secreting bacteria show that ExoU ubiquitination results in its co-localization with endosomal markers. This could reflect an attempt of the infected cell to target ExoU for degradation in order to protect itself from its aggressive cytotoxic action.


    Organizational Affiliation

    Bacterial Pathogenesis Group, Institut de Biologie Structurale-IBS, Université Grenoble I, Grenoble, France.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
SPCUA127Pseudomonas aeruginosaMutation(s): 0 
Gene Names: 
UniProt
Find proteins for O66100 (Pseudomonas aeruginosa)
Explore O66100 
Go to UniProtKB:  O66100
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO66100
Protein Feature View
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  • Reference Sequence
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
EXOUB660Pseudomonas aeruginosaMutation(s): 0 
Gene Names: exoUpepAEXC2IPC1494_14325IPC1595_24955IPC607_30280RS14
UniProt
Find proteins for O34208 (Pseudomonas aeruginosa)
Explore O34208 
Go to UniProtKB:  O34208
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO34208
Protein Feature View
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  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A L-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.94 Å
  • R-Value Free: 0.264 
  • R-Value Work: 0.208 
  • R-Value Observed: 0.211 
  • Space Group: C 1 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 154.887α = 90
b = 52.799β = 127.18
c = 121.811γ = 90
Software Package:
Software NamePurpose
REFMACrefinement
XDSdata reduction
XSCALEdata scaling
PHENIXphasing

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-04-18
    Type: Initial release
  • Version 1.1: 2012-05-30
    Changes: Other