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Error‐prone DNA polymerase IV is controlled by the stress‐response sigma factor, RpoS, in Escherichia coli
Author(s) -
Layton Jill C.,
Foster Patricia L.
Publication year - 2003
Publication title -
molecular microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.857
H-Index - 247
eISSN - 1365-2958
pISSN - 0950-382X
DOI - 10.1046/j.1365-2958.2003.03704.x
Subject(s) - rpos , biology , repressor lexa , repressor , sigma factor , mutant , dna polymerase , microbiology and biotechnology , genetics , mutation , gene , escherichia coli , gene expression , rna polymerase , promoter
Summary An insertion in rpoS , which encodes the general stress response sigma factor σ 38 , was isolated as an antimutator for ‘stationary‐phase’ or ‘adaptive’ mutation. In the rpoS mutant strain the levels of error‐prone DNA polymerase Pol IV were reduced. Pol IV is encoded by the dinB gene, and the amount of its transcript was also reduced in rpoS mutant cells. In wild‐type cells, the levels of Pol IV increased in late stationary phase and stayed elevated for several days of continuous incubation, whereas in rpoS defective cells Pol IV was not induced and declined during prolonged incubation. Even in cells missing LexA, the repressor of dinB , maximum Pol IV expression required RpoS. These results suggest that induction of Pol IV is part of a cellular response to starvation and other stresses.