Abstract
Transcript mapping and studies with lacZ translational fusions have shown that the pdhR gene (formerly genA) is the proximal gene of the pdhR-aceE-aceF-lpd operon encoding the pyruvate dehydrogenase (PDH) complex of Escherichia coli. A pdhR-lpd read-through transcript (7.4 kb) initiating at the pyruvate-inducible pdh promoter, and a smaller lpd transcript (1.7 kb) initiating at the independent lpd promoter, were identified. Evidence showing that the pdhR gene product negatively regulates the synthesis of the PdhR protein and the PDH complex via the pdh promoter was obtained, with pyruvate (or a derivative) serving as the putative inducing coeffector. The partially purified PdhR protein was also found to specifically retard and protect DNA fragments containing the pdh promoter region. The pdh promoter was not strongly controlled by ArcA, FNR or CRP.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Acetyltransferases / biosynthesis
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Acetyltransferases / genetics*
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Amino Acid Sequence
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Bacterial Proteins / genetics*
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Bacterial Proteins / metabolism
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Base Sequence
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DNA, Bacterial / genetics
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DNA, Bacterial / metabolism
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Dihydrolipoamide Dehydrogenase / biosynthesis
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Dihydrolipoamide Dehydrogenase / genetics*
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Dihydrolipoyllysine-Residue Acetyltransferase
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Enzyme Induction
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Escherichia coli / enzymology
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Escherichia coli / genetics*
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Escherichia coli Proteins*
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Gene Expression Regulation, Bacterial
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Genes, Bacterial*
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Ketoglutarate Dehydrogenase Complex / biosynthesis
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Ketoglutarate Dehydrogenase Complex / genetics*
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Molecular Sequence Data
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Operon*
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Promoter Regions, Genetic
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Pyruvate Dehydrogenase Complex / biosynthesis
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Pyruvate Dehydrogenase Complex / genetics*
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Recombinant Fusion Proteins / biosynthesis
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Regulatory Sequences, Nucleic Acid
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Repressor Proteins / genetics
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Transcription Factors / genetics*
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Transcription Factors / metabolism
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Transcription, Genetic
Substances
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Bacterial Proteins
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DNA, Bacterial
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Escherichia coli Proteins
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PdhR protein, E coli
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Pyruvate Dehydrogenase Complex
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Recombinant Fusion Proteins
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Repressor Proteins
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Transcription Factors
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Ketoglutarate Dehydrogenase Complex
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lpd protein, E coli
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Dihydrolipoamide Dehydrogenase
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Acetyltransferases
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Dihydrolipoyllysine-Residue Acetyltransferase