1JYO

Structure of the Salmonella Virulence Effector SptP in Complex with its Secretion Chaperone SicP


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.224 

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This is version 1.2 of the entry. See complete history

Literature

Maintenance of an unfolded polypeptide by a cognate chaperone in bacterial type III secretion.

Stebbins, C.E.Galan, J.E.

(2001) Nature 414: 77-81

  • DOI: 10.1038/35102073

  • PubMed Abstract: 
  • Many bacterial pathogens use a type III protein secretion system to deliver virulence effector proteins directly into the host cell cytosol, where they modulate cellular processes. A requirement for the effective translocation of several such effecto ...

    Many bacterial pathogens use a type III protein secretion system to deliver virulence effector proteins directly into the host cell cytosol, where they modulate cellular processes. A requirement for the effective translocation of several such effector proteins is the binding of specific cytosolic chaperones, which typically interact with discrete domains in the virulence factors. We report here the crystal structure at 1.9 A resolution of the chaperone-binding domain of the Salmonella effector protein SptP with its cognate chaperone SicP. The structure reveals that this domain is maintained in an extended, unfolded conformation that is wound around three successive chaperone molecules. Short segments from two different SptP molecules are juxtaposed by the chaperones, where they dimerize across a hydrophobic interface. These results imply that the chaperones associated with the type III secretion system maintain their substrates in a secretion-competent state that is capable of engaging the secretion machinery to travel through the type III apparatus in an unfolded or partially folded manner.


    Organizational Affiliation

    Section of Microbial Pathogenesis, Boyer Center for Molecular Medicine, Yale School of Medicine, New Haven, Connecticut 06336, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
SicP
A, B, C, D
130Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)Gene Names: sicP
Find proteins for P0CL16 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Go to UniProtKB:  P0CL16
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
protein tyrosine phosphatase SptP
E, F
105Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)Gene Names: sptP
EC: 3.1.3.48
Find proteins for P74873 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Go to UniProtKB:  P74873
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.9 Å
  • R-Value Free: 0.258 
  • R-Value Work: 0.224 
  • Space Group: C 1 2 1
Unit Cell:
Length (Å)Angle (°)
a = 167.489α = 90.00
b = 49.582β = 121.95
c = 138.142γ = 90.00
Software Package:
Software NamePurpose
CNSrefinement
DENZOdata reduction
SOLVEphasing
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2001-11-07
    Type: Initial release
  • Version 1.1: 2008-04-27
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance