Structural analysis of Xanthomonas XopD provides insights into substrate specificity of ubiquitin-like protein proteases

J Biol Chem. 2007 Mar 2;282(9):6773-82. doi: 10.1074/jbc.M608730200. Epub 2007 Jan 3.


XopD (Xanthomonas outer protein D), a type III secreted effector from Xanthomonas campestris pv. vesicatoria, is a desumoylating enzyme with strict specificity for its plant small ubiquitin-like modifier (SUMO) substrates. Based on SUMO sequence alignments and peptidase assays with various plant, yeast, and mammalian SUMOs, we identified residues in SUMO that contribute to XopD/SUMO recognition. Further predictions regarding the enzyme/substrate specificity were made by solving the XopD crystal structure. By incorporating structural information with sequence alignments and enzyme assays, we were able to elucidate determinants of the rigid SUMO specificity exhibited by the Xanthomonas virulence factor XopD.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Outer Membrane Proteins / chemistry*
  • Bacterial Outer Membrane Proteins / metabolism
  • Binding Sites
  • Crystallography, X-Ray
  • Protein Conformation
  • Sequence Alignment
  • Small Ubiquitin-Related Modifier Proteins / chemistry*
  • Small Ubiquitin-Related Modifier Proteins / metabolism
  • Substrate Specificity
  • Virulence Factors / chemistry
  • Xanthomonas / chemistry*


  • Bacterial Outer Membrane Proteins
  • Small Ubiquitin-Related Modifier Proteins
  • Virulence Factors