The homologous regulators ANR of Pseudomonas aeruginosa and FNR of Escherichia coli have overlapping but distinct specificities for anaerobically inducible promoters.

Details

Serval ID
serval:BIB_E3AD495DC64E
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
The homologous regulators ANR of Pseudomonas aeruginosa and FNR of Escherichia coli have overlapping but distinct specificities for anaerobically inducible promoters.
Journal
Microbiology
Author(s)
Winteler H.V., Haas D.
ISSN
1350-0872 (Print)
ISSN-L
1350-0872
Publication state
Published
Issued date
1996
Volume
142
Number
3
Pages
685-693
Language
english
Abstract
The anaerobic transcriptional regulator ANR induces the arginine deiminase and denitrification pathways in Pseudomonas aeruginosa during oxygen limitation. The homologous activator FNR of Escherichia coli, when introduced into an anr mutant of P. aeruginosa, could functionally replace ANR for anaerobic growth on nitrate but not for anaerobic induction of arginine deiminase. In an FNR-positive E. coli strain, the ANR-dependent promoter of the arcDABC operon, which encodes the enzymes of the arginine deiminase pathway, was not expressed. To analyse systematically these distinct induction patterns, a lacZ promoter-probe, broad-host-range plasmid containing various -40 regions (the ANR/FNR recognition sequences) and -10 promoter sequences was constructed. These constructs were tested in P. aeruginosa and in E. coli expressing either ANR or FNR. In conjunction with the consensus -10 hexamer of E. coli sigma 70 RNA polymerase (TATAAT), the consensus FNR site (TTGAT ..... ATCAA) was recognized efficiently by ANR and FNR in both hosts. By contrast, when promoters contained the Arc box (TTGAC .... ATCAG), which is found in the arcDABC promoter, or a symmetrical mutant FNR site (CTGAT .... ATCAG), ANR was a more effective activator than was FNR. Conversely, an extended 22 bp, fully symmetrical FNR site allowed better activation with FNR than with ANR. Combination of the arc promoter -10 sequence (CCTAAT) with the Arc box or the consensus FNR site resulted in good ANR-dependent expression in P. aeruginosa but gave practically no expression in E. coli, suggesting that RNA polymerase of P. aeruginosa differs from the E. coli enzyme in -10 recognition specificity. In conclusion, ANR and FNR are able to activate the RNA polymerases of P. aeruginosa and E. coli when the -40 and -10 promoter elements ae identical or close to the E. coli consensus sequences.
Keywords
Anaerobiosis/genetics, Bacterial Proteins/genetics, Base Sequence, Cloning, Molecular, DNA-Binding Proteins, Escherichia coli/genetics, Escherichia coli Proteins, Genes, Bacterial, Iron-Sulfur Proteins/genetics, Molecular Sequence Data, Promoter Regions, Genetic/genetics, Pseudomonas aeruginosa/genetics, Sequence Alignment, Trans-Activators, Transcription Factors/genetics, Transcription, Genetic
Pubmed
Web of science
Open Access
Yes
Create date
25/01/2008 17:01
Last modification date
20/08/2019 16:07
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