Abstract
Induction of the Escherichia coli K-12 ynfEFGHI operon in response to anaerobiosis is repressed by nitrate ions. In this study, we show that the global transcription factor FNR is a class II activator at the ynfEFGHI promoter and that NarL represses activation by binding to a single target that overlaps the promoter -10 element. Electromobility shift assays show that NarL does not prevent RNA polymerase binding and suggest that repression may involve a quaternary NarL-FNR-RNA polymerase-promoter complex.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Anaerobiosis
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Base Sequence
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DNA-Binding Proteins / physiology*
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DNA-Directed RNA Polymerases / metabolism
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Electrophoretic Mobility Shift Assay
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Escherichia coli K12 / genetics
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Escherichia coli K12 / physiology*
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Escherichia coli Proteins / physiology*
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Gene Expression Regulation, Bacterial*
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Iron-Sulfur Proteins / physiology*
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Molecular Sequence Data
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Operon
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Promoter Regions, Genetic*
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Protein Binding
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Transcriptional Activation
Substances
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DNA-Binding Proteins
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Escherichia coli Proteins
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FNR protein, E coli
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Iron-Sulfur Proteins
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NarL protein, E coli
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DNA-Directed RNA Polymerases