3HW2

Crystal structure of the SifA-SKIP(PH) complex


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.3 Å
  • R-Value Free: 0.309 
  • R-Value Work: 0.240 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Interaction between the SifA virulence factor and its host target skip is essential for salmonella pathogenesis

Diacovich, L.Dumont, A.Lafitte, D.Soprano, E.Guilhon, A.-A.Bignon, C.Gorvel, J.-P.Bourne, Y.Meresse, S.

(2009) J.Biol.Chem. 284: 33151-33160

  • DOI: 10.1074/jbc.M109.034975

  • PubMed Abstract: 
  • SifA is a Salmonella effector that is translocated into infected cells by the pathogenicity island 2-encoded type 3 secretion system. SifA is a critical virulence factor. Previous studies demonstrated that, upon translocation, SifA binds the pleckstr ...

    SifA is a Salmonella effector that is translocated into infected cells by the pathogenicity island 2-encoded type 3 secretion system. SifA is a critical virulence factor. Previous studies demonstrated that, upon translocation, SifA binds the pleckstrin homology motif of the eukaryotic host protein SKIP. In turn, the SifA-SKIP complex regulates the mobilization of the molecular motor kinesin-1 on the bacterial vacuole. SifA exhibits multiple domains containing functional motifs. Here we performed a molecular dissection and a mutational study of SifA to evaluate the relative contribution of the different domains to SifA functions. Biochemical and crystallographic analysis confirmed that the N-terminal domain of SifA is sufficient to interact with the pleckstrin homology domain of SKIP, forming a 1:1 complex with a micromolar dissociation constant. Mutation of the tryptophan residue in the WXXXE motif, which has been proposed to mimic active form of GTPase, deeply affected the stability and the translocation of SifA while mutations of the glutamic residue had no functional impact. A SifA L130D mutant that does not bind SKIP showed a DeltasifA-like phenotype both in infected cells and in the mouse model of infection. We concluded that the WXXXE motif is essential for maintaining the tertiary structure of SifA, the functions of which require the interaction with the eukaryotic protein SKIP.


    Organizational Affiliation

    Centre d'Immunologie de Marseille-Luminy, CNRS UMR 6102, INSERM U631, Université de la Méditerranée, Parc Scientifique de Luminy, Case 906, 13288 Marseille Cedex 9.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Protein sifA
A
336Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720)Mutation(s): 0 
Gene Names: sifA
Find proteins for Q56061 (Salmonella typhimurium (strain LT2 / SGSC1412 / ATCC 700720))
Go to UniProtKB:  Q56061
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Pleckstrin homology domain-containing family M member 2
B
105Homo sapiensMutation(s): 0 
Gene Names: PLEKHM2 (KIAA0842, SKIP)
Find proteins for Q8IWE5 (Homo sapiens)
Go to Gene View: PLEKHM2
Go to UniProtKB:  Q8IWE5
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.3 Å
  • R-Value Free: 0.309 
  • R-Value Work: 0.240 
  • Space Group: P 21 21 2
Unit Cell:
Length (Å)Angle (°)
a = 91.799α = 90.00
b = 110.866β = 90.00
c = 44.274γ = 90.00
Software Package:
Software NamePurpose
XDSdata reduction
SCALAdata scaling
MOLREPphasing
ADSCdata collection
REFMACrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2009-11-03
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Advisory, Version format compliance
  • Version 1.2: 2014-02-26
    Type: Derived calculations