GacA-controlled activation of promoters for small RNA genes in Pseudomonas fluorescens.

Details

Serval ID
serval:BIB_718E837C59E0
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
GacA-controlled activation of promoters for small RNA genes in Pseudomonas fluorescens.
Journal
Applied and Environmental Microbiology
Author(s)
Humair B., Wackwitz B., Haas D.
ISSN
1098-5336[electronic], 0099-2240[linking]
Publication state
Published
Issued date
2010
Peer-reviewed
Oui
Volume
76
Number
5
Pages
1497-1506
Language
english
Abstract
The Gac/Rsm signal transduction pathway positively regulates secondary metabolism, production of extracellular enzymes, and biocontrol properties of Pseudomonas fluorescens CHA0 via the expression of three noncoding small RNAs, termed RsmX, RsmY, and RsmZ. The architecture and function of the rsmY and rsmZ promoters were studied in vivo. A conserved palindromic upstream activating sequence (UAS) was found to be necessary but not sufficient for rsmY and rsmZ expression and for activation by the response regulator GacA. A poorly conserved linker region located between the UAS and the -10 promoter sequence was also essential for GacA-dependent rsmY and rsmZ expression, suggesting a need for auxiliary transcription factors. One such factor involved in the activation of the rsmZ promoter was identified as the PsrA protein, previously recognized as an activator of the rpoS gene and a repressor of fatty acid degradation. Furthermore, the integration host factor (IHF) protein was found to bind with high affinity to the rsmZ promoter region in vitro, suggesting that DNA bending contributes to the regulated expression of rsmZ. In an rsmXYZ triple mutant, the expression of rsmY and rsmZ was elevated above that found in the wild type. This negative feedback loop appears to involve the translational regulators RsmA and RsmE, whose activity is antagonized by RsmXYZ, and several hypothetical DNA-binding proteins. This highly complex network controls the expression of the three small RNAs in response to cell physiology and cell population densities.
Keywords
Bacterial Proteins/physiology, Base Sequence, DNA, Bacterial/metabolism, Electrophoretic Mobility Shift Assay, Gene Expression Regulation, Bacterial, Models, Biological, Molecular Sequence Data, Promoter Regions, Genetic, Protein Binding, Pseudomonas fluorescens/physiology, RNA, Bacterial/biosynthesis, RNA, Untranslated/biosynthesis, Transcriptional Activation
Pubmed
Web of science
Open Access
Yes
Create date
11/01/2011 14:21
Last modification date
20/08/2019 14:30
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