Genetic and molecular evidence that the Pseudomonas syringae type III effector protein AvrRpt2 is a cysteine protease

Mol Microbiol. 2003 Sep;49(6):1537-46. doi: 10.1046/j.1365-2958.2003.03666.x.


Upon delivery to the plant cell during infection, the Pseudomonas syringae effector protein AvrRpt2 undergoes proteolytic processing, enhances pathogen virulence and causes the elimination of the Arabidopsis RIN4 protein. A structure-prediction method was employed in order to investigate possible biochemical functions of AvrRpt2. Results of a secondary structure prediction algorithm suggest that the functional C-terminal portion of AvrRpt2 is a cysteine protease. Mutation of predicted catalytic residues within this portion of AvrRpt2 abolished in planta processing, elimination of Arabidopsis RIN4, and the ability to trigger an RPS2-specific resistance response. These data indicate that AvrRpt2 is most likely a sequence divergent cysteine protease whose activity is required for elimination of RIN4 during infection.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Arabidopsis / immunology
  • Arabidopsis / metabolism
  • Arabidopsis / microbiology
  • Arabidopsis Proteins / metabolism
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / genetics*
  • Bacterial Proteins / metabolism*
  • Carrier Proteins / metabolism
  • Catalytic Domain
  • Cysteine Endopeptidases* / chemistry
  • Cysteine Endopeptidases* / genetics
  • Cysteine Endopeptidases* / metabolism
  • DNA, Bacterial / genetics
  • Electrophoresis, Polyacrylamide Gel
  • Gene Expression
  • Immunoblotting
  • Intracellular Signaling Peptides and Proteins
  • Molecular Sequence Data
  • Mutagenesis, Site-Directed
  • Protein Structure, Secondary
  • Pseudomonas / enzymology*
  • Pseudomonas / genetics*
  • Pseudomonas / pathogenicity
  • Structural Homology, Protein
  • Transformation, Bacterial / genetics


  • Arabidopsis Proteins
  • Bacterial Proteins
  • Carrier Proteins
  • DNA, Bacterial
  • Intracellular Signaling Peptides and Proteins
  • RIN4 protein, Arabidopsis
  • RPS2 protein, Arabidopsis
  • avrRpt2 protein, Pseudomonas syringae
  • Cysteine Endopeptidases