RNase H overproduction allows the expression of stress-induced genes in the absence of topoisomerase I

Bokun Cheng, Shan Rui, Chengling Ji, Vivien W. Gong, Tina K. Van Dyk, Marc Drolet, Yuk Ching Tse-Dinh

Research output: Contribution to journalArticle

18 Scopus citations


Induction of stress proteins in response to heat shock was found to be reduced significantly in Escherichia coli with ΔtopA mutation. RNase H overexpression in the ΔtopA mutant partially restored the σ32-dependent induction of stress genes in response to high temperature and ethanol. The presence of overexpressed RNase H also improved the survival rate of the ΔtopA mutant after high temperature and oxidative challenges. Topoisomerase I is likely required during stress response for preventing accumulation of transcription-driven hypernegative supercoiling and R-loop formation at induced stress genes loci.

Original languageEnglish (US)
Pages (from-to)237-242
Number of pages6
JournalFEMS Microbiology Letters
Issue number2
StatePublished - Apr 25 2003



  • R-loop
  • RNase H
  • Stress response
  • Top A
  • Topoisomerase I

ASJC Scopus subject areas

  • Microbiology
  • Molecular Biology
  • Genetics

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