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. 1978 Feb;25(2):562–569. doi: 10.1128/jvi.25.2.562-569.1978

Purification and structures of recombining and replicating bacteriophage T7 DNA.

L Langman, V Paetkau
PMCID: PMC353969  PMID: 342727

Abstract

During the infection of Escherichia coli by bacteriophage T7, there is a gradual conversion of host DNA to T7 DNA. Recombination and replication occur during this time. We have devised a new way of examining the physical structures of the intermediates of these processes. It is based on the observation that there are no sites in T7 DNA susceptible to cleavage by the restriction endonuclease EcoRI. E. coli DNA, on the other hand, is susceptible to degradation by EcoRI. Thus, phage and host DNA can be separated by sucrose gradient centrifugation after treatment with EcoRI. Concatemeric T7 DNA contains a high proportion of branched, gapped, and whiskered structures. These appear to be intermediates of replication and recombination. This approach also monitors the conversion process from host to T7 DNA.

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Selected References

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

  1. Broker T. R., Lehman I. R. Branched DNA molecules: intermediates in T4 recombination. J Mol Biol. 1971 Aug 28;60(1):131–149. doi: 10.1016/0022-2836(71)90453-0. [DOI] [PubMed] [Google Scholar]
  2. Delius H., Howe C., Kozinski A. W. Structure of the replicating DNA from bacteriophage T4. Proc Natl Acad Sci U S A. 1971 Dec;68(12):3049–3053. doi: 10.1073/pnas.68.12.3049. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Hausmann R. Bacteriophage T7 genetics. Curr Top Microbiol Immunol. 1976;75:77–110. doi: 10.1007/978-3-642-66530-1_3. [DOI] [PubMed] [Google Scholar]
  4. Holliday R. Molecular aspects of genetic exchange and gene conversion. Genetics. 1974 Sep;78(1):273–287. doi: 10.1093/genetics/78.1.273. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Inman R. B., Schnös M. Structure of branch points in replicating DNA: presence of single-stranded connections in lambda DNA branch points. J Mol Biol. 1971 Mar 14;56(2):319–325. doi: 10.1016/0022-2836(71)90467-0. [DOI] [PubMed] [Google Scholar]
  6. Kerr C., Sadowski P. D. The involvement of genes 3,4,5 and 6 in genetic recombination in bacteriophage T7. Virology. 1975 May;65(1):281–285. doi: 10.1016/0042-6822(75)90031-8. [DOI] [PubMed] [Google Scholar]
  7. Lee M., Miller R. C., Jr, Scraba D., Paetkau V. The essential role of bacteriophage T7 endonuclease (gene 3) in molecular recombination. J Mol Biol. 1976 Jul 15;104(4):883–888. doi: 10.1016/0022-2836(76)90189-3. [DOI] [PubMed] [Google Scholar]
  8. Lee M., Miller R. C., Jr T7 exonuclease (gene 6) is necessary for molecular recombination of bacteriophage T7. J Virol. 1974 Nov;14(5):1040–1048. doi: 10.1128/jvi.14.5.1040-1048.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Miller R. C., Jr, Lee M. The role of bacteriophage T7 exonuclease (gene 6) in genetic recombination and production of concatemers. J Mol Biol. 1976 Feb 25;101(2):223–234. doi: 10.1016/0022-2836(76)90374-0. [DOI] [PubMed] [Google Scholar]
  10. Morgan A. R., Pulleyblank D. E. Native and denatured DNA, cross-linked and palindromic DNA and circular covalently-closed DNA analysed by a sensitive fluorometric procedure. Biochem Biophys Res Commun. 1974 Nov 27;61(2):396–403. doi: 10.1016/0006-291x(74)90970-x. [DOI] [PubMed] [Google Scholar]
  11. Paetkau V., Langman L. A quantitative, batch hydroxyapatite method for analyzing native and denatured DNA at room temperature. Anal Biochem. 1975 May 12;65(1-2):525–532. doi: 10.1016/0003-2697(75)90537-0. [DOI] [PubMed] [Google Scholar]
  12. Paetkau V., Langman L., Bradley R., Scraba D., Miller R. C., Jr Folded, concatenated genomes as replication intermediates of bacteriophage T7 DNA. J Virol. 1977 Apr;22(1):130–141. doi: 10.1128/jvi.22.1.130-141.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Paetkau V., Langman L., Miller R. C., Jr The origin of nascent single-stranded fragments in replicating TM DNA. J Mol Biol. 1975 Nov 15;98(4):719–737. doi: 10.1016/s0022-2836(75)80006-4. [DOI] [PubMed] [Google Scholar]
  14. Potter H., Dressler D. On the mechanism of genetic recombination: electron microscopic observation of recombination intermediates. Proc Natl Acad Sci U S A. 1976 Sep;73(9):3000–3004. doi: 10.1073/pnas.73.9.3000. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Powling A., Knippers R. Recombination of bacteriophage T7 in vivo. Mol Gen Genet. 1976 Nov 24;149(1):63–71. doi: 10.1007/BF00275961. [DOI] [PubMed] [Google Scholar]
  16. Powling A., Knippers R. Some functions involved in bacteriophage T7 genetic recombination. Mol Gen Genet. 1974;134(2):173–180. doi: 10.1007/BF00268418. [DOI] [PubMed] [Google Scholar]
  17. Sadowski P. D., Kerr C. Degradation of Escherichia coli B deoxyribonucleic acid after infection with deoxyribonucleic acid-defective amber mutants of bacteriophage T7. J Virol. 1970 Aug;6(2):149–155. doi: 10.1128/jvi.6.2.149-155.1970. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Tanaka T., Weisblum B. Construction of a colicin E1-R factor composite plasmid in vitro: means for amplification of deoxyribonucleic acid. J Bacteriol. 1975 Jan;121(1):354–362. doi: 10.1128/jb.121.1.354-362.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Thomas C. A., Jr, Kelly T. J., Jr, Rhoades M. The intracellular forms of T7 and P22 DNA molecules. Cold Spring Harb Symp Quant Biol. 1968;33:417–424. doi: 10.1101/sqb.1968.033.01.048. [DOI] [PubMed] [Google Scholar]
  20. Tsujimoto Y., Ogawa H. Intermediates in genetic recombination of bacteriophage T7 DNA. J Mol Biol. 1977 Jan 25;109(3):423–426. doi: 10.1016/s0022-2836(77)80021-1. [DOI] [PubMed] [Google Scholar]
  21. Wolfson J., Dressler D., Magazin M. Bacteriophage T7 DNA replication: a linear replicating intermediate (gradient centrifugation-electron microscopy-E. coli-DNA partial denaturation). Proc Natl Acad Sci U S A. 1972 Feb;69(2):499–504. doi: 10.1073/pnas.69.2.499. [DOI] [PMC free article] [PubMed] [Google Scholar]

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