Stationary phase induction of dnaN and recF, two genes of Escherichia coli involved in DNA replication and repair

Magda Villarroya, Ignacio Pérez-Roger, Fernando Macián, M. Eugenia Armengod

Research output: Contribution to journalArticle

30 Scopus citations

Abstract

The β subunit of DNA polymerase III holoenzyme, the Escherichia coli chromosomal replicase, is a sliding DNA clamp responsible for tethering the polymerase to DNA and endowing it with high processivity. The gene encoding β, dnaN, maps between dnnA and recF, which are involved in initiation of DNA replication at oriC and resumption of DNA replication at disrupted replication forks, respectively. In exponentially growing cells, dnaN and recF are expressed predominantly from the dnaA promoters. However, we have found that stationary phase induction of the dnaN promoters drastically changes the expression pattern of the dnaA operon genes. As a striking consequence, synthesis of the β subunit and RecF protein increases when cell metabolism is slowing down. Such an induction is dependent on the stationary phase σ factor, RpoS, although the accumulation of this factor alone is not sufficient to activate the dnaN promoters. These promoters are located in DNA regions without static bending, and the -35 hexamer element is essential for their RpoS-dependent induction. Our results suggest that stationary phase-dependent mechanisms have evolved in order to coordinate expression of dnaN and recF independently of the dnaA regulatory region. These mechanisms might be part of a developmental programme aimed at maintaining DNA integrity under stress conditions.

Original languageEnglish (US)
Pages (from-to)1829-1837
Number of pages9
JournalEMBO Journal
Volume17
Issue number6
DOIs
StatePublished - Mar 16 1998
Externally publishedYes

Keywords

  • DNA polymerase III holoenzyme
  • DNA replication
  • RpoS
  • Stationary phase
  • dnaA-dnaN-recF operon

ASJC Scopus subject areas

  • Neuroscience(all)
  • Molecular Biology
  • Biochemistry, Genetics and Molecular Biology(all)
  • Immunology and Microbiology(all)

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