Promoter recognition and activation by the global response regulator CbrB in Pseudomonas aeruginosa.

Détails

ID Serval
serval:BIB_9F010FA5017F
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Promoter recognition and activation by the global response regulator CbrB in Pseudomonas aeruginosa.
Périodique
Journal of Bacteriology
Auteur(s)
Abdou L., Chou H.T., Haas D., Lu C.D.
ISSN
1098-5530 (Electronic)
ISSN-L
0021-9193
Statut éditorial
Publié
Date de publication
2011
Volume
193
Numéro
11
Pages
2784-2792
Langue
anglais
Résumé
In Pseudomonas aeruginosa, the CbrA/CbrB two-component system is instrumental in the maintenance of the carbon-nitrogen balance and for growth on carbon sources that are energetically less favorable than the preferred dicarboxylate substrates. The CbrA/CbrB system drives the expression of the small RNA CrcZ, which antagonizes the repressing effects of the catabolite repression control protein Crc, an RNA-binding protein. Dicarboxylates appear to cause carbon catabolite repression by inhibiting the activity of the CbrA/CbrB system, resulting in reduced crcZ expression. Here we have identified a conserved palindromic nucleotide sequence that is present in upstream activating sequences (UASs) of promoters under positive control by CbrB and σ(54) RNA polymerase, especially in the UAS of the crcZ promoter. Evidence for recognition of this palindromic sequence by CbrB was obtained in vivo from mutational analysis of the crcZ promoter and in vitro from electrophoretic mobility shift assays using crcZ promoter fragments and purified CbrB protein truncated at the N terminus. Integration host factor (IHF) was required for crcZ expression. CbrB also activated the lipA (lipase) promoter, albeit less effectively, apparently by interacting with a similar but less conserved palindromic sequence in the UAS of lipA. As expected, succinate caused CbrB-dependent catabolite repression of the lipA promoter. Based on these results and previously published data, a consensus CbrB recognition sequence is proposed. This sequence has similarity to the consensus NtrC recognition sequence, which is relevant for nitrogen control.
Mots-clé
Bacterial Proteins/metabolism, Binding Sites, DNA Mutational Analysis, DNA, Bacterial/genetics, DNA, Bacterial/metabolism, Electrophoretic Mobility Shift Assay, Gene Expression Regulation, Bacterial, Integration Host Factors/metabolism, Lipase/metabolism, Promoter Regions, Genetic, Protein Binding, Pseudomonas aeruginosa/genetics, RNA Polymerase Sigma 54/metabolism, Transcription Factors/metabolism, Transcriptional Activation
Pubmed
Web of science
Création de la notice
16/02/2012 10:49
Dernière modification de la notice
03/03/2018 20:01
Données d'usage