SigmaS-dependent gene expression at the onset of stationary phase in Escherichia coli: function of sigmaS-dependent genes and identification of their promoter sequences.

ABSTRACT: 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

SUBMITTER: Lacour S 

PROVIDER: S-EPMC523212 | biostudies-literature | 2004 Nov

REPOSITORIES: biostudies-literature