Selective cloning of genes encoding RNase H from Salmonella typhimurium, Saccharomyces cerevisiae and Escherichia coli rnh mutant.
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.
Itaya
M
M
Laboratory of Molecular Genetics, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892.
McKelvin
D
D
Chatterjie
S K
SK
Crouch
R J
RJ
D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004722:Endoribonucleases / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics*; D005798:Genes, Bacterial; D005800:Genes, Fungal; D008969:Molecular Sequence Data; D009154:Mutation; D009693:Nucleic Acid Hybridization; D010641:Phenotype; D010957:Plasmids; D011401:Promoter Regions, Genetic; D016914:Ribonuclease H; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D012486:Salmonella typhimurium / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
D004722:Endoribonucleases; D016914:Ribonuclease H