Essential roles of three enhancer sites in sigma-54-dependent transcription by the nitric oxide sensing regulatory protein NorR

Nick Tucker, T. Ghosh, M. Bush, X. Zhang, Ray Dixon

Research output: Contribution to journalArticle

30 Citations (Scopus)
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Abstract

The bacterial activator protein NorR binds to enhancer-like elements, upstream of the promoter site, and activates 54-dependent transcription of genes that encode nitric oxide detoxifying enzymes (NorVW), in response to NO stress. Unique to the norVW promoter in Escherichia coli is the presence of three enhancer sites associated with a binding site for 54-RNA polymerase. Here we show that all three sites are required for NorR-dependent catalysis of open complex formation by 54-RNAP holoenzyme (E54). We demonstrate that this is essentially due to the need for all three enhancers for maximal ATPase activity of NorR, energy from which is used to remodel the closed E54 complex and allow melting of the promoter DNA. We also find that site-specific DNA binding per se promotes oligomerisation but the DNA flanking the three sites is needed to further stabilise the functional higher order oligomer of NorR at the enhancers.
Original languageEnglish
Pages (from-to)1182-1194
Number of pages13
JournalNucleic Acids Research
Volume38
Issue number4
Early online date2 Dec 2009
DOIs
Publication statusPublished - 2010

Keywords

  • bacterial activator protein
  • gene transcription
  • Escherichia coli
  • DNA binding
  • nitric oxide

Activities

  • 1 Key-note speaker and plenary lectures at conferences

Analysis of free radicals, radical modifications and redox signalling

Nicholas Tucker (Invited speaker)

18 Apr 201119 Apr 2011

Activity: Participating in or organising an event typesKey-note speaker and plenary lectures at conferences

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