title: Ribonuclease H: a ubiquitous activity in virions of ribonucleic acid tumor viruses.
abstract: Ten ribonucleic acid (RNA) tumor viruses grown in five different host cell species and three non-oncogenic viruses from three different virus groups have been examined for ribonuclease H content. Three different substrates were used to assay ribonuclease H: calf thymus [(3)H]RNA-deoxyribonucleic acid (DNA) hybrid prepared with denatured calf thymus DNA and Escherichia coli DNA-directed RNA polymerase, (3)H-polydenylic acid [(3)H-poly(A)] complexed to polydeoxythymidylic acid [poly(dT)], and (3)H-polyuridylic acid [(3)H-poly(U)] complexed to polydeoxyadenylic acid [poly(dA)]. All ten RNA tumor viruses contained ribonuclease H activity which degraded the RNA of both the calf thymus hybrid and poly(A)-poly(dT), whereas only the ribonuclease H in the Moloney strain of murine sarcoma-leukemia virus and in RD-feline leukemia virus hydrolyzed the RNA strand of poly(U)-poly(dA). No appreciable ribonuclease H activity was detected in influenza, Sendai, or vesicular stomatitis virus. The ribonuclease H and RNA-directed DNA polymerase activities in Moloney murine sarcoma-leukemia virus were inseparable by phosphocellulose chromatography or glycerol gradient centrifugation, but appeared to be partially separated by diethylaminoethyl-cellulose chromatography.
mesh_terms: D000818:Animals; D002417:Cattle; D002474:Cell-Free System; D002499:Centrifugation, Density Gradient; D002845:Chromatography; D002848:Chromatography, DEAE-Cellulose; D004247:DNA; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology; D017988:Gammaretrovirus / Q000201:enzymology; D005990:Glycerol; D005256:Leukemia Virus, Feline / Q000201:enzymology; D008979:Moloney murine leukemia virus / Q000201:enzymology; D009691:Nucleic Acid Denaturation; D009693:Nucleic Acid Hybridization; D009858:Oncogenic Viruses / Q000201:enzymology*; D011119:Polynucleotides / Q000378:metabolism; D012313:RNA / Q000378:metabolism; D012328:RNA Viruses / Q000201:enzymology*; D012194:RNA-Directed DNA Polymerase / Q000302:isolation & purification / Q000378:metabolism; D012260:Ribonucleases / Q000302:isolation & purification / Q000378:metabolism*; D013950:Thymus Gland; D014316:Tritium
chemical_list: D011119:Polynucleotides; D014316:Tritium; D012313:RNA; D004247:DNA; D012194:RNA-Directed DNA Polymerase; D012321:DNA-Directed RNA Polymerases; D012260:Ribonucleases; D005990:Glycerol