JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Supplemental material
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Lacour, S.
Right arrow Articles by Landini, P.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Lacour, S.
Right arrow Articles by Landini, P.
Journal of Bacteriology, November 2004, p. 7186-7195, Vol. 186, No. 21
0021-9193/04/$08.00+0     DOI: 10.1128/JB.186.21.7186-7195.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

{sigma}S-Dependent Gene Expression at the Onset of Stationary Phase in Escherichia coli: Function of {sigma}S-Dependent Genes and Identification of Their Promoter Sequences{dagger}

Stephan Lacour1 and Paolo Landini1,2*

Swiss Federal Institute of Environmental Technology (EAWAG), Dübendorf, Switzerland,1 University of Milan, Milan, Italy2

Received 16 June 2004/ Accepted 27 July 2004

The {sigma}S subunit of RNA polymerase, the product of the rpoS gene, controls the expression of genes responding to starvation and cellular stresses. Using gene array technology, we investigated rpoS-dependent expression at the onset of stationary phase in Escherichia coli grown in rich medium. Forty-one genes were expressed at significantly lower levels in an rpoS mutant derived from the MG1655 strain; for 10 of these, we also confirmed rpoS and stationary-phase dependence by reverse transcription-PCR. Only seven genes (dps, osmE, osmY, sodC, rpsV, wrbA, and yahO) had previously been recognized as rpoS dependent. Several newly identified rpoS-dependent genes are involved in the uptake and metabolism of amino acids, sugars, and iron. Indeed, the rpoS mutant strain shows severely impaired growth on some sugars such as fructose and N-acetylglucosamine. The rpoS gene controls the production of indole, which acts as a signal molecule in stationary-phase cells, via regulation of the tnaA-encoded tryptophanase enzyme. Genes involved in protein biosynthesis, encoding the ribosome-associated protein RpsV (sra) and the initiation factor IF-1 (infA), were also induced in an rpoS-dependent fashion. Using primer extension, we determined the promoter sequences of a selection of rpoS-regulated genes representative of different functional classes. Significant fractions of these promoters carry sequence features specific for E{sigma}S recognition of the –10 region, such as cytosines at positions –13 (70%) and –12 (30%) as well as a TG motif located upstream of the –10 region (50%), thus supporting the TGN0-2C(C/T)ATA(C/A)T consensus sequence recently proposed for {sigma}S.

* Corresponding author. Mailing address: Department of Molecular Biosciences and Biotechnology, University of Milan, Via Celoria 26, 20133 Milan, Italy. Phone: 39-02-50315028. Fax: 39-02-50315044. E-mail: paolo.landini{at}unimi.it.

{dagger} Supplemental material for this article may be found at http://jb.asm.org/.

Journal of Bacteriology, November 2004, p. 7186-7195, Vol. 186, No. 21
0021-9193/04/$08.00+0     DOI: 10.1128/JB.186.21.7186-7195.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 2004 by the American Society for Microbiology. All rights reserved.