A mixed incoherent feed-forward loop contributes to the regulation of bacterial photosynthesis genes

RNA Biol. 2013 Mar;10(3):347-52. doi: 10.4161/rna.23769. Epub 2013 Feb 7.


Living cells use a variety of regulatory network motifs for accurate gene expression in response to changes in their environment or during differentiation processes. In Rhodobacter sphaeroides, a complex regulatory network controls expression of photosynthesis genes to guarantee optimal energy supply on one hand and to avoid photooxidative stress on the other hand. Recently, we identified a mixed incoherent feed-forward loop comprising the transcription factor PrrA, the sRNA PcrZ and photosynthesis target genes as part of this regulatory network. This point-of-view provides a comparison to other described feed-forward loops and discusses the physiological relevance of PcrZ in more detail.

Keywords: Rhodobacter; feed-forward loop; gene regulation; oxygen tension; photosynthesis; redox regulation; small RNAs.

MeSH terms

  • Bacterial Proteins / metabolism*
  • Gene Expression Regulation, Bacterial*
  • Gene Regulatory Networks*
  • Genes, Bacterial
  • Oxidative Stress / genetics
  • Photosynthesis / genetics*
  • RNA, Bacterial / metabolism
  • RNA, Small Untranslated / metabolism*
  • Rhodobacter sphaeroides / genetics*
  • Rhodobacter sphaeroides / metabolism
  • Transcription Factors / metabolism


  • Bacterial Proteins
  • RNA, Bacterial
  • RNA, Small Untranslated
  • Transcription Factors