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. 1978 Nov;5(11):4245–4261. doi: 10.1093/nar/5.11.4245

T7 gene 6 exonuclease has an RNase H activity.

K Shinozaki, T Okazaki
PMCID: PMC342746  PMID: 364424

Abstract

T7 gene 6 exonuclease has been shown to have an RNase H activity as well as a double-strand specific DNase activity by the following experiments: The RNase H activity coelutes with the DNase activity from DEAE-cellulose, phosphocellulose, hydroxyapatite, and Sephadex G-200 columns. Gene 6 exonuclease specified by a T7 strain with a temperature sensitive mutation in gene 6 has an extremely heat-labile RNase H activity as well as a heat-labile DNase activity. T7 gene 6 exonuclease degrades the RNA region of a poly(A) . poly(dT) hybrid polymer exonucleolytically from the 5' terminus, releasing a ribonucleoside 5'-monophosphate product. When the RNA strand of a 0X174 RNA . DNA hybrid molecule synthesized with E. coli RNA polymerase is degraded, a ribonucleoside triphosphate is produced from the 5'-triphosphate terminus. Participation of T7 gene 6 exonuclease in the removal of primer RNA in discontinuous replication of T7 DNA is discussed.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Alberts B., Sternglanz R. Recent excitement in the DNA replication problem. Nature. 1977 Oct 20;269(5630):655–661. doi: 10.1038/269655a0. [DOI] [PubMed] [Google Scholar]
  2. BERNS K. I., THOMAS C. A., Jr ISOLATION OF HIGH MOLECULAR WEIGHT DNA FROM HEMOPHILUS INFLUENZAE. J Mol Biol. 1965 Mar;11:476–490. doi: 10.1016/s0022-2836(65)80004-3. [DOI] [PubMed] [Google Scholar]
  3. Baltimore D., Smoler D. F. Association of an endoribonuclease with the avian myeloblastosis virus deoxyribonucleic acid polymerase. J Biol Chem. 1972 Nov 25;247(22):7282–7287. [PubMed] [Google Scholar]
  4. Berkower I., Leis J., Hurwitz J. Isolation and characterization of an endonuclease from Escherichia coli specific for ribonucleic acid in ribonucleic acid-deoxyribonucleic acid hybrid structures. J Biol Chem. 1973 Sep 10;248(17):5914–5921. [PubMed] [Google Scholar]
  5. Friedberg E. C., Lehman I. R. Excision of thymine dimers by proteolytic and amber fragments of E. coli DNA polymerase I. Biochem Biophys Res Commun. 1974 May 7;58(1):132–139. doi: 10.1016/0006-291x(74)90901-2. [DOI] [PubMed] [Google Scholar]
  6. Fujii-Kawata I., Miura K. I. Segments of genome of viruses containing double-stranded ribonucleic acid. J Mol Biol. 1970 Jul 28;51(2):247–253. doi: 10.1016/0022-2836(70)90140-3. [DOI] [PubMed] [Google Scholar]
  7. Keller W., Crouch R. Degradation of DNA RNA hybrids by ribonuclease H and DNA polymerases of cellular and viral origin. Proc Natl Acad Sci U S A. 1972 Nov;69(11):3360–3364. doi: 10.1073/pnas.69.11.3360. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Kelly R. B., Cozzarelli N. R., Deutscher M. P., Lehman I. R., Kornberg A. Enzymatic synthesis of deoxyribonucleic acid. XXXII. Replication of duplex deoxyribonucleic acid by polymerase at a single strand break. J Biol Chem. 1970 Jan 10;245(1):39–45. [PubMed] [Google Scholar]
  9. Kerr C., Sadowski P. D. Gene 6 exonuclease of bacteriophage T7. I. Purification and properties of the enzyme. J Biol Chem. 1972 Jan 10;247(1):305–310. [PubMed] [Google Scholar]
  10. Kerr C., Sadowski P. D. Gene 6 exonuclease of bacteriophage T7. II. Mechanism of the reaction. J Biol Chem. 1972 Jan 10;247(1):311–318. [PubMed] [Google Scholar]
  11. Konrad E. B., Lehman I. R. A conditional lethal mutant of Escherichia coli K12 defective in the 5' leads to 3' exonuclease associated with DNA polymerase I. Proc Natl Acad Sci U S A. 1974 May;71(5):2048–2051. doi: 10.1073/pnas.71.5.2048. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Kurosawa Y., Ogawa T., Hirose S., Okazaki T., Okazaki R. Mechanism of DNA chain growth. XV. RNA-linked nascent DNA pieces in Escherichia coli strains assayed with spleen exonuclease. J Mol Biol. 1975 Aug 25;96(4):653–664. doi: 10.1016/0022-2836(75)90144-8. [DOI] [PubMed] [Google Scholar]
  13. MIYAZAWA Y., THOMAS C. A., Jr NUCLEOTIDE COMPOSITION OF SHORT SEGMENTS OF DNA MOLECULES. J Mol Biol. 1965 Feb;11:223–237. doi: 10.1016/s0022-2836(65)80053-5. [DOI] [PubMed] [Google Scholar]
  14. Machida Y., Okazaki T., Okazaki R. Discontinuous replication of replicative form DNA from bacteriophage phiX174. Proc Natl Acad Sci U S A. 1977 Jul;74(7):2776–2779. doi: 10.1073/pnas.74.7.2776. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Miyamoto C., Denhardt D. T. Evidence for the presence of ribonucleotides at the 5' termini of some DNA molecules isolated from Escherichia coli polAex2. J Mol Biol. 1977 Nov;116(4):681–707. doi: 10.1016/0022-2836(77)90266-2. [DOI] [PubMed] [Google Scholar]
  16. Ogawa T., Hirose S., Okazaki T., Okazaki R. Mechanism of DNA chain growth XVI. Analyses of RNA-linked DNA pieces in Escherichia coli with polynucleotide kinase. J Mol Biol. 1977 May 5;112(1):121–140. doi: 10.1016/s0022-2836(77)80160-5. [DOI] [PubMed] [Google Scholar]
  17. Portier C., van Rapenbusch R., Minh-Nguy-Thang, Grunberg-Manago M. Quaternary structure of polynucleotide phosphorylase from Escherichia coli. Eur J Biochem. 1973 Dec 3;40(1):77–87. doi: 10.1111/j.1432-1033.1973.tb03170.x. [DOI] [PubMed] [Google Scholar]
  18. RICHARDSON C. C., LEHMAN I. R., KORNBERG A. A DEOXYRIBONUCLEIC ACID PHOSPHATASE-EXONUCLEASE FROM ESCHERICHIA COLI. II. CHARACTERIZATION OF THE EXONUCLEASE ACTIVITY. J Biol Chem. 1964 Jan;239:251–258. [PubMed] [Google Scholar]
  19. Roychoudhury R. Transcriptional role in deoxyribonucleic acid replication. Nature of primer function of newly synthesized ribonucleic acid in vitro. J Biol Chem. 1973 Dec 25;248(24):8465–8473. [PubMed] [Google Scholar]
  20. Schekman R., Wickner W., Westergaard O., Brutlag D., Geider K., Bertsch L. L., Kornberg A. Initiation of DNA synthesis: synthesis of phiX174 replicative form requires RNA synthesis resistant to rifampicin. Proc Natl Acad Sci U S A. 1972 Sep;69(9):2691–2695. doi: 10.1073/pnas.69.9.2691. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Shinozaki K., Okazaki T. RNA-linked nascent DNA pieces in T7 phage-infected Escherichia coli cells. I. Role of gene 6 exonuclease in removal of the linked RNA. Mol Gen Genet. 1977 Sep 9;154(3):263–267. doi: 10.1007/BF00571281. [DOI] [PubMed] [Google Scholar]
  22. Studier F. W. The genetics and physiology of bacteriophage T7. Virology. 1969 Nov;39(3):562–574. doi: 10.1016/0042-6822(69)90104-4. [DOI] [PubMed] [Google Scholar]
  23. Sugino A., Hirose S., Okazaki R. RNA-linked nascent DNA fragments in Escherichia coli. Proc Natl Acad Sci U S A. 1972 Jul;69(7):1863–1867. doi: 10.1073/pnas.69.7.1863. [DOI] [PMC free article] [PubMed] [Google Scholar]
  24. Tamanoi F., Okazaki T., Okazaki R. Persistence of RNA attached to nascent short DNA pieces in Bacillus subtilis cells defective in DNA polymerase I. Biochem Biophys Res Commun. 1977 Jul 11;77(1):290–297. doi: 10.1016/s0006-291x(77)80195-2. [DOI] [PubMed] [Google Scholar]
  25. Weatherford S. C., Weisberg L. S., Achord D. T., Apirion D. Separation of Escherichia coli ribonucleases on a DNA agarose column and the identification of an RNase H activity. Biochem Biophys Res Commun. 1972 Dec 4;49(5):1307–1315. doi: 10.1016/0006-291x(72)90609-2. [DOI] [PubMed] [Google Scholar]

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