Structure of Salmonella effector protein SopB N-terminal domain in complex with host Rho GTPase Cdc42

J Biol Chem. 2012 Apr 13;287(16):13348-55. doi: 10.1074/jbc.M111.331330. Epub 2012 Feb 23.


SopB is a type III secreted Salmonella effector protein with phosphoinositide phosphatase activity and a distinct GTPase binding domain. The latter interacts with host Cdc42, an essential Rho GTPase that regulates critical events in eukaryotic cytoskeleton organization and membrane trafficking. Structural and biochemical analysis of the SopB GTPase binding domain in complex with Cdc42 shows for the first time that SopB structurally and functionally mimics a host guanine nucleotide dissociation inhibitor (GDI) by contacting key residues in the regulatory switch regions of Cdc42 and slowing Cdc42 nucleotide exchange.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / chemistry*
  • Bacterial Proteins / metabolism*
  • Calorimetry
  • Crystallography, X-Ray
  • Guanine / chemistry
  • Guanine / metabolism
  • Humans
  • Leucine / chemistry
  • Leucine / metabolism
  • Molecular Mimicry
  • Nucleotides / chemistry
  • Nucleotides / metabolism*
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Salmonella enterica / enzymology*
  • Signal Transduction / physiology
  • Structure-Activity Relationship
  • cdc42 GTP-Binding Protein / metabolism*
  • rho GTP-Binding Proteins / metabolism*


  • Bacterial Proteins
  • Nucleotides
  • Guanine
  • SopB protein, Salmonella
  • cdc42 GTP-Binding Protein
  • rho GTP-Binding Proteins
  • Leucine

Associated data

  • PDB/4DID