Altered topoisomerase activities may be involved in the regulation of DNA supercoiling in aerobic-anaerobic transitions in Escherichia coli

Sonia Cortassa, Miguel Antonio Aon

Research output: Contribution to journalArticle

Abstract

This study uncovers a new mechanism of regulation of DNA supercoiling operative in vivo upon an aerobic-anaerobic transition in Escherichia coli. Exponentially growing aerobic batch cultures were subjected to a shift to anaerobic conditions. The ratio [ATP]/[ADP] remained essentially constant at 8.5 in the aerobic culture and after a transition to anaerobiosis while DNA supercoiling increased noticeably upon anaerobiosis. This result indicated that the mechanism of regulation of DNA supercoiling by the [ATP]/[ADP] ratio was not operative. The increase in DNA supercoiling was followed by a large decrease in the DNA-relaxing activity of topoisomerase I while gyrase activity remained relatively constant. This decrease in the activity of topoisomerase I is likely to be responsible for the increase in DNA supercoiling.

Original languageEnglish (US)
Pages (from-to)115-124
Number of pages10
JournalMolecular and Cellular Biochemistry
Volume126
Issue number2
DOIs
StatePublished - Sep 1 1993

Keywords

  • DNA supercoiling
  • DNA topoisomerases
  • Escherichia coli
  • [ATP]/[ADP] ratio
  • aerobic anaerobic transitions

ASJC Scopus subject areas

  • Molecular Biology
  • Clinical Biochemistry
  • Cell Biology

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