Substitutions at Auxiliary Operator O3 Enhance Repression by Nitrate-Responsive Regulator NarL at Synthetic lac Control Regions in Escherichia coli K-12
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چکیده
منابع مشابه
Synthetic lac operator substitutions for studying the nitrate- and nitrite-responsive NarX-NarL and NarQ-NarP two-component regulatory systems of Escherichia coli K-12.
The NarX and NarQ sensor-histidine kinases control phosphorylation of the NarL and NarP response regulators in response to the respiratory oxidants nitrate and nitrite. Target operon transcription is activated by the Fnr protein in response to anaerobiosis, and it is further activated and/or repressed by the phospho-NarL and phospho-NarP proteins, which bind to heptamer DNA sequences. The locat...
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Hierarchical control ensures that facultative bacteria preferentially use the available respiratory electron acceptor with the most positive standard redox potential. Thus, nitrate is used before other electron acceptors such as fumarate for anaerobic respiration. Nitrate regulation is mediated by the NarX-NarL two-component system, which activates the transcription of operons encoding nitrate ...
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The capR (lon) product controls expression of the gal operon independently of the galR repressor. Previously, mutations of the gal operon have been isolated that are semiconstitutive and alter response to the capR and/or capT product. Such mutants imply the existence of a distinct site in the operon that responds to capR (capT) control. This mutation could be either in a site near the operator-...
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In Escherichia coli K-12 the expression of many genes is controlled by the oxygen-responsive transcription factor FNR and the nitrate- and nitrite-responsive two-component systems NarXL and NarPQ. Here, the ydhY gene is shown to be the first gene of a six-gene operon (ydhYVWXUT) that encodes proteins predicted to be components of an oxidoreductase. Mapping the ydhY-T transcript start and site-d...
متن کاملFnr, NarP, and NarL regulation of Escherichia coli K-12 napF (periplasmic nitrate reductase) operon transcription in vitro.
The expression of several Escherichia coli operons is activated by the Fnr protein during anaerobic growth and is further controlled in response to nitrate and nitrite by the homologous response regulators, NarL and NarP. Among these operons, the napF operon, encoding a periplasmic nitrate reductase, has unique features with respect to its Fnr-, NarL-, and NarP-dependent regulation. First, the ...
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ژورنال
عنوان ژورنال: Journal of Bacteriology
سال: 2008
ISSN: 0021-9193,1098-5530
DOI: 10.1128/jb.01431-07