Molecular characterization of the promoter of osmY, an rpoS-dependent gene.
The osmY gene, which encodes a periplasmic protein with an apparent M(r) of 22,000, is induced by both osmotic and growth phase signals. We demonstrate here that osmY expression is regulated at the level of transcription and that transcription initiates 242 nucleotides upstream of the osmY open reading frame. Relative to the transcriptional start site, 5' deletions up to -36 did not inhibit osmY expression. 3' deletions that extended into the untranslated leader region affected the overall level of osmY::lacZ expression but did not affect inducibility. 5' and 3' deletions that extended past the transcriptional start region essentially abolished osmY expression, suggesting that there is a single promoter region. A putative promoter was identified, and its -10 region, TATATT, closely resembles the sigma 70 consensus -10 sequence, TATAAT. However, we show that osmY is not absolutely dependent on a functional sigma 70 for its expression. Since osmY expression does require rpoS (R. Hengge-Aronis, R. Lange, N. Henneberg, and D. Fischer, J. Bacteriol. 175:259-265, 1993), which encodes a stationary-phase sigma factor, sigma S (K. Tanaka, Y. Takayanagi, N. Fujita, A. Ishihama, and H. Takahashi, Proc. Natl. Acad. Sci. USA 90:3511-3515, 1993), E sigma S may be the form of RNA polymerase responsible for transcription of osmY.
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Section of Microbiology, University of California, Davis 95616.
Brems
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Villarejo
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D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D004252:DNA Mutational Analysis; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D009994:Osmolar Concentration; D033902:Periplasmic Binding Proteins; D011401:Promoter Regions, Genetic / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D017384:Sequence Deletion; D012808:Sigma Factor / Q000378:metabolism*; D015398:Signal Transduction; D014158:Transcription, Genetic
D001426:Bacterial Proteins; D002352:Carrier Proteins; D029968:Escherichia coli Proteins; D033902:Periplasmic Binding Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D012808:Sigma Factor; C069567:sigma factor KatF protein, Bacteria; C074783:osmY protein, E coli; C081775:RNA polymerase sigma 70; D012321:DNA-Directed RNA Polymerases