Selective cloning of genes encoding RNase H from Salmonella typhimurium, Saccharomyces cerevisiae and Escherichia coli rnh mutant

Mitsuhiro Itaya, Dorothy McKelvin, Sunil K. Chatterjie, Robert J. Crouch

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We have cloned genes encoding RNase H from Escherichia coli rnh mutants, Salmonella typhimurium and Saccharomyces cerevisiae. Selection was accomplished by suppression of the temperature-sensitive growth phenotype of Escherichia coli strains containing the rnh-339::cat and either recB270 (Ts) or recC271 (Ts) mutations. RNases H from E. coli and S. typhimurium contained 155 amino acid residues and differed at only 11 positions. The S. cerevisiae and E. coli RNases H were about 30% homologous. A comparison of the amino acid sequences of several RNases H from cellular and retroviral sources revealed some strongly conserved regions as well as variable regions; the carboxyl-terminus was particularly variable. The overlapping, divergent promoter gene organization found in E. coli was observed to be present in S. typhimurium.

Original languageEnglish
Pages (from-to)438-445
Number of pages8
JournalMGG Molecular & General Genetics
Issue number3
Publication statusPublished - 1991 Jul 1



  • RNase H
  • Saccharomyces cerevisiae
  • Salmonella typhimurium

ASJC Scopus subject areas

  • Genetics

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