Characterization of the OxyR regulon of Neisseria gonorrhoeae

Mol Microbiol. 2007 Jan;63(1):54-68. doi: 10.1111/j.1365-2958.2006.05478.x. Epub 2006 Nov 27.


OxyR regulates the expression of the majority of H(2)O(2) responses in Gram-negative organisms. In a previous study we reported the OxyR-dependent derepression of catalase expression in the human pathogen Neisseria gonorrhoeae. In the present study we used microarray expression profiling of N. gonorrhoeae wild-type strain 1291 and an oxyR mutant strain to define the OxyR regulon. In addition to katA (encoding catalase), only one other locus displayed a greater than two-fold difference in expression in the wild type : oxyR comparison. This locus encodes an operon of two genes, a putative peroxiredoxin/glutaredoxin (Prx) and a putative glutathione oxidoreductase (Gor). Mutant strains were constructed in which each of these genes was inactivated. A previous biochemical study in Neisseria meningitidis had confirmed function of the glutaredoxin/peroxiredoxin. Assay of the wild-type 1291 cell free extract confirmed Gor activity, which was lost in the gor mutant strain. Phenotypic analysis of the prx mutant strain in H(2)O(2) killing assays revealed increased resistance, presumably due to upregulation of alternative defence mechanisms. The oxyR, prx and gor mutant strains were deficient in biofilm formation, and the oxyR and prx strains had decreased survival in cervical epithelial cells, indicating a key role for the OxyR regulon in these processes.

Publication types

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

MeSH terms

  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / physiology*
  • Escherichia coli Proteins / genetics
  • Escherichia coli Proteins / physiology*
  • Gene Expression Regulation, Bacterial / physiology*
  • Molecular Sequence Data
  • Neisseria gonorrhoeae / enzymology
  • Neisseria gonorrhoeae / genetics*
  • Oligonucleotide Array Sequence Analysis
  • Oxidative Stress
  • Regulon / genetics*
  • Regulon / physiology
  • Repressor Proteins / genetics
  • Repressor Proteins / physiology*
  • Transcription Factors / genetics
  • Transcription Factors / physiology*


  • DNA-Binding Proteins
  • Escherichia coli Proteins
  • Repressor Proteins
  • Transcription Factors
  • oxyR protein, E coli

Associated data

  • GENBANK/AE004969