The coordinate regulation of multiple terminal oxidases by the Pseudomonas putida ANR global regulator

Environ Microbiol. 2008 Jul;10(7):1690-702. doi: 10.1111/j.1462-2920.2008.01586.x. Epub 2008 Mar 12.

Abstract

Pseudomonas putida KT2440 contains a branched aerobic respiratory chain with multiple terminal oxidases. Their relative proportion varies according to environmental conditions. The role of the oxygen-responsive ANR global regulator on expression of these terminal oxidases was analysed. During exponential growth in a highly aerated complete medium, ANR activated expression of the Cbb3-1 terminal oxidase (equivalent to Pseudomonas aeruginosa Cbb3-2), but had little role on expression of other terminal oxidases. In early stationary phase, or under oxygen limitation, inactivation of the anr gene led to increased expression of the bo(3)-type cytochrome (Cyo) and cyanide-insensitive (CIO) terminal oxidases, and to a much lower expression of Cbb3-1. DNase I footprints identified ANR binding sites at the promoters for these oxidases. Their location suggests that ANR is a transcriptional activator of Cbb3-1 genes and a repressor of CIO genes, consistent with expression data. ANR binding sites at the promoter for Cyo genes suggests a complex regulation in combination with other factors. Therefore, ANR coordinates expression of Cyo, CIO and Cbb3-1, but does not influence cytochrome aa3 and Cbb3-2 terminal oxidases under the conditions analysed. Functional assays showed that Cyo has a leading role during aerobic exponential growth, while Cbb3-1 becomes very important in stationary phase.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / metabolism
  • Bacterial Proteins / physiology*
  • Electron Transport Complex IV / antagonists & inhibitors
  • Electron Transport Complex IV / biosynthesis
  • Electron Transport Complex IV / genetics
  • Electron Transport Complex IV / metabolism*
  • Gene Expression Regulation, Bacterial*
  • Gene Expression Regulation, Enzymologic
  • Genes, Regulator
  • Pseudomonas putida / enzymology
  • Pseudomonas putida / genetics
  • Pseudomonas putida / metabolism*
  • Trans-Activators / metabolism
  • Trans-Activators / physiology*
  • Transcription Factors / physiology

Substances

  • Bacterial Proteins
  • Trans-Activators
  • Transcription Factors
  • ANR protein, Pseudomonas aeruginosa
  • cbb3 oxidase
  • Electron Transport Complex IV