RpoS-dependent promoters require guanosine tetraphosphate for induction even in the presence of high levels of sigma(s).
RpoS-dependent promoters require ppGpp for induction in the stationary phase. This has been thought to be a simple consequence of final sigma(S) itself requiring ppGpp for its production. By using four model promoters requiring final sigma(S) for normal induction in the stationary phase, we demonstrate that final sigma(S)-dependent promoters require ppGpp even in the presence of high levels of final sigma(S) produced ectopically. Similar to final sigma(70)-dependent promoters under positive control by ppGpp, the requirement of final sigma(S)-dependent promoters for this alarmone is bypassed by specific "stringent" mutations in the beta-subunit of RNA polymerase. The results suggest that stationary phase induction of both final sigma(S)- and final sigma(70)-dependent genes requires the stringent control modulon and that stringency confers dual control on the RpoS regulon by affecting promoter activity and the levels of the required final sigma-factor.
Kvint
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Department of Cell and Molecular Biology-Microbiology, Göteborg University, Box 462, 405 30 Göteborg, Sweden.
Farewell
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Nyström
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D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D029968:Escherichia coli Proteins; D005838:Genotype; D006159:Guanosine Tetraphosphate / Q000378:metabolism*; D007700:Kinetics; D008565:Membrane Proteins; D016296:Mutagenesis; D010957:Plasmids; D011401:Promoter Regions, Genetic; D012808:Sigma Factor / Q000378:metabolism*; D014161:Transduction, Genetic; D001616:beta-Galactosidase / Q000235:genetics / Q000378:metabolism
D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D008565:Membrane Proteins; D012808:Sigma Factor; C116144:UspB protein, E coli; C069567:sigma factor KatF protein, Bacteria; D006159:Guanosine Tetraphosphate; D012321:DNA-Directed RNA Polymerases; D001616:beta-Galactosidase