Modulation of acid-induced amino acid decarboxylase gene expression by hns in Escherichia coli.
Biodegradative arginine decarboxylase and lysine decarboxylase, encoded by adi and cadA, respectively, are induced to maximal levels when Escherichia coli is grown anaerobically in rich medium at acidic pH. Mutants formed by transposon mutagenesis, namely, GNB725, GNB729, GNB88, GNB824, and GNB837, exhibited considerably elevated expression at pH 8.0 compared with the corresponding parental strain. Southern hybridization and chromosome mapping showed that the above mutants contained a transposon within the hns gene. Several plasmids from an E. coli library able to complement these mutants by restoring normal pH induction were independently isolated and were found to contain the hns gene. These results suggest a role for the DNA-binding protein H-NS in affecting the activation of these acid-induced genes.
Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77251.
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Shi
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Waasdorp
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Bennett
D001425:Bacterial Outer Membrane Proteins / Q000235:genetics*; D001426:Bacterial Proteins / Q000235:genetics; D002262:Carboxy-Lyases / Q000235:genetics*; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D005816:Genetic Complementation Test; D016296:Mutagenesis; D015183:Restriction Mapping
D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; C031908:H-NS protein, bacteria; D002262:Carboxy-Lyases; C021520:lysine decarboxylase; C019722:arginine decarboxylase