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. 1977 Jul;131(1):145–152. doi: 10.1128/jb.131.1.145-152.1977

Properties of the relaxation complex of supercoiled deoxyribonucleic acid and protein of R plasmid NR1 in Escherichia coli.

D D Womble, R H Rownd
PMCID: PMC235403  PMID: 326756

Abstract

Some properties of the supercoiled deoxyribonucleic acid (DNA)-protein relaxation complex of the R plasmid NR1, which contains more than one origin for DNA replication, were examined. The percentage of complexed NR1 molecules that can be converted to the relaxed (nicked) form appeared to be unaffected by the conditions under which the host cells were cultured. However, the percentage of supercoiled NR1 DNA that can be relaxed was highly dependent on the method used to prepare the DNA and the agents used to induce relaxation. Our data suggest that 100% of NR1 molecules may exist in situ as DNA-protein relaxation complexes. An RTF-Tc segregant of NR1, which has deleted the r-determinants component of the NR1 and therefore does not contain the two origins of replication located in the r-determinants, has indistinguishable relaxation properties in comparison with NR1 itself.

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Selected References

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

  1. Clewell D. B., Helinski D. E. Existence of the colicinogenic factor-sex factor ColI-b-P9 as a supercoiled circular DNA-protein relaxation complex. Biochem Biophys Res Commun. 1970 Oct 9;41(1):150–156. doi: 10.1016/0006-291x(70)90481-x. [DOI] [PubMed] [Google Scholar]
  2. Clewell D. B., Helinski D. R. Effect of growth conditions on the formation of the relaxation complex of supercoiled ColE1 deoxyribonucleic acid and protein in Escherichia coli. J Bacteriol. 1972 Jun;110(3):1135–1146. doi: 10.1128/jb.110.3.1135-1146.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Clewell D. B., Helinski D. R. Properties of a supercoiled deoxyribonucleic acid-protein relaxation complex and strand specificity of the relaxation event. Biochemistry. 1970 Oct 27;9(22):4428–4440. doi: 10.1021/bi00824a026. [DOI] [PubMed] [Google Scholar]
  4. Clewell D. B., Helinski D. R. Supercoiled circular DNA-protein complex in Escherichia coli: purification and induced conversion to an opern circular DNA form. Proc Natl Acad Sci U S A. 1969 Apr;62(4):1159–1166. doi: 10.1073/pnas.62.4.1159. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Cohen S. N., Miller C. A. Non-chromosomal antibiotic resistance in bacteria. 3. Isolation of the discrete transfer unit of the R-factor R1. Proc Natl Acad Sci U S A. 1970 Oct;67(2):510–516. doi: 10.1073/pnas.67.2.510. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Collins J., Williams P., Helinski D. R. Plasmid ColE1 DNA replication in Escherichia coli strains temperature-sensitive for DNA replication. Mol Gen Genet. 1975;136(4):273–289. doi: 10.1007/BF00341713. [DOI] [PubMed] [Google Scholar]
  7. Freifelder D. Molecular weights of coliphages and coliphage DNA. IV. Molecular weights of DNA from bacteriophages T4, T5 and T7 and the general problem of determination of M. J Mol Biol. 1970 Dec 28;54(3):567–577. doi: 10.1016/0022-2836(70)90127-0. [DOI] [PubMed] [Google Scholar]
  8. Helinski D. R. Plasmid determined resistance to antibiotics: molecular properties of R factors. Annu Rev Microbiol. 1973;27:437–470. doi: 10.1146/annurev.mi.27.100173.002253. [DOI] [PubMed] [Google Scholar]
  9. Humphreys G. O., Grindley N. D., Anderson E. S. DNA--protein complexes of delta-mediated transfer systems. Biochim Biophys Acta. 1972 Dec 6;287(2):355–360. doi: 10.1016/0005-2787(72)90385-1. [DOI] [PubMed] [Google Scholar]
  10. Kasamatsu H., Rownd R. Replication of R-factors in Proteus mirabilis: replication under relaxed control. J Mol Biol. 1970 Aug;51(3):473–489. doi: 10.1016/0022-2836(70)90002-1. [DOI] [PubMed] [Google Scholar]
  11. Kline B. C., Miller J. R. Detection of nonintegrated plasmid deoxyribonucleic acid in the folded chromosome of Escherichia coli: physiochemical approach to studying the unit of segregation. J Bacteriol. 1975 Jan;121(1):165–172. doi: 10.1128/jb.121.1.165-172.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Kupersztoch-Portnoy Y. M., Lovett M. A., Helinski D. R. Strand and site specificity of the relaxation event for the relaxation complex of the antibiotic resistance plasmid R6K. Biochemistry. 1974 Dec 31;13(27):5484–5490. doi: 10.1021/bi00724a005. [DOI] [PubMed] [Google Scholar]
  13. Kupersztoch-Portnoy Y. M., Miklos G. L., Helinski D. R. Properties of the relaxation complexes of supercoiled deoxyribonucleic acid and protein of the R plasmids R64, R28K, and R6K. J Bacteriol. 1974 Oct;120(1):545–548. doi: 10.1128/jb.120.1.545-548.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Lovett M. A., Guiney D. G., Helinski D. R. Relaxation complexes of plasmids ColE1 and ColE2: unique site of the nick in the open circular DNA of the relaxed complexes. Proc Natl Acad Sci U S A. 1974 Oct;71(10):3854–3857. doi: 10.1073/pnas.71.10.3854. [DOI] [PMC free article] [PubMed] [Google Scholar]
  15. Lovett M. A., Katz L., Helinski D. R. Unidirectional replication of plasmid ColE1 DNA. Nature. 1974 Sep 27;251(5473):337–340. doi: 10.1038/251337a0. [DOI] [PubMed] [Google Scholar]
  16. Lovett M. A., Sparks R. B., Helinski D. R. Bidirectional replication of plasmid R6K DNA in Escherichia coli; correspondence between origin of replication and position of single-strand break in relaxed complex. Proc Natl Acad Sci U S A. 1975 Aug;72(8):2905–2909. doi: 10.1073/pnas.72.8.2905. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Morris C. F., Hashimoto H., Mickel S., Rownd R. Round of replication mutant of a drug resistance factor. J Bacteriol. 1974 Jun;118(3):855–866. doi: 10.1128/jb.118.3.855-866.1974. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Morris C. F., Hershberger C. L., Rownd R. Strand-specific nick in open circular R-factor deoxyribonucleic acid: attachment of the linear strand to a proteinaceous cellular component. J Bacteriol. 1973 Apr;114(1):300–308. doi: 10.1128/jb.114.1.300-308.1973. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Nakaya R., Rownd R. Transduction of R factors by a Proteus mirabilis bacteriophage. J Bacteriol. 1971 Jun;106(3):773–783. doi: 10.1128/jb.106.3.773-783.1971. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Perlman D., Rownd R. H. Transition of R factor NR1 in Proteus mirabilis: molecular structure and replication of NR1 deoxyribonucleic acid. J Bacteriol. 1975 Sep;123(3):1013–1034. doi: 10.1128/jb.123.3.1013-1034.1975. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Perlman D., Rownd R. H. Two origins of replication in composite R plasmid DNA. Nature. 1976 Jan 29;259(5541):281–284. doi: 10.1038/259281a0. [DOI] [PubMed] [Google Scholar]
  22. Rownd R., Kasamatsu H., Mickel S. The molecular nature and replication of drug resistance factors of the Enterobacteriaceae. Ann N Y Acad Sci. 1971 Jun 11;182:188–206. doi: 10.1111/j.1749-6632.1971.tb30656.x. [DOI] [PubMed] [Google Scholar]
  23. Rownd R., Nakaya R., Nakamura A. Molecular nature of the drug-resistance factors of the Enterobacteriaceae. J Mol Biol. 1966 Jun;17(2):376–393. doi: 10.1016/s0022-2836(66)80149-3. [DOI] [PubMed] [Google Scholar]
  24. Rownd R., Perlman D., Hashimoto H., Mickel S., Applebaum E., Taylor D. Dissociation and reassociation of the transfer factor and resistance determinants of R factors as a mechanism of gene amplification in bacteria. Johns Hopkins Med J Suppl. 1973;2:115–128. [PubMed] [Google Scholar]
  25. Schubach W. H., Whitmer J. D., Davern C. I. Genetic control of DNA initiation in Escherichia coli. J Mol Biol. 1973 Feb 25;74(2):205–221. doi: 10.1016/0022-2836(73)90107-1. [DOI] [PubMed] [Google Scholar]
  26. Sugino Y., Tomizawa J., Kakefuda T. Location of non-DNA components of closed circular colicin E1 plasmid DNA. Nature. 1975 Feb 20;253(5493):652–654. doi: 10.1038/253652a0. [DOI] [PubMed] [Google Scholar]
  27. Tanak N., Cramer J. H., Rownd R. H. EcoRI restriction endonuclease map of the composite R plasmid NR1. J Bacteriol. 1976 Jul;127(1):619–636. doi: 10.1128/jb.127.1.619-636.1976. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Womble D. D., Taylor D. P., Rownd R. H. Method for obtaining more-accurate covalently closed circular plasmid-to-chromosome ratios from bacterial lysates by dye-buoyant density centrifugation. J Bacteriol. 1977 Apr;130(1):148–153. doi: 10.1128/jb.130.1.148-153.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Womble D. D., Warren R. L., Rownd R. H. Partially supercoiled replication intermediates of R plasmid DNA are resistant to relaxation. Nature. 1976 Dec 16;264(5587):676–678. doi: 10.1038/264676a0. [DOI] [PubMed] [Google Scholar]

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