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. 1983 May;80(9):2447–2451. doi: 10.1073/pnas.80.9.2447

Conformational flexibility of junctions between contiguous B- and Z-DNAs in supercoiled plasmids.

C K Singleton, J Klysik, R D Wells
PMCID: PMC393842  PMID: 6302683

Abstract

The junctions between contiguous right- and left-handed helical DNA segments in supercoiled plasmids are shown to exhibit both sequence- and superhelical-dependent conformational flexibility. The nonalternating (purine-pyrimidine) tetranucleotide d(G-A-T-C), which is imbedded within a (dC-dG) tract and exists as a junction at low-density values, may be adopting a left-handed helix under the influence of higher negative supercoiling. The effect of supercoiling on the transition from a right- to a left-handed state for (dC-dG)n inserts, where n = 16, 13, and 5, also was evaluated. Only moderate amounts of superhelicity (-0.03 to -0.075) are required for formation and stabilization of left-handed DNA even for the (dC-dG) region of 10 dC X dG base pairs. Finally, we demonstrate that junction formation within a BamHI restriction site causes a drastic inhibition (greater than 80%) of cleavage by this restriction endonuclease.

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Selected References

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

  1. Bauer W. R. Structure and reactions of closed duplex DNA. Annu Rev Biophys Bioeng. 1978;7:287–313. doi: 10.1146/annurev.bb.07.060178.001443. [DOI] [PubMed] [Google Scholar]
  2. Depew D. E., Wang J. C. Conformational fluctuations of DNA helix. Proc Natl Acad Sci U S A. 1975 Nov;72(11):4275–4279. doi: 10.1073/pnas.72.11.4275. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Dodgson J. B., Wells R. D. Action of single-strand specific nucleases on model DNA heteroduplexes of defined size and sequence. Biochemistry. 1977 May 31;16(11):2374–2379. doi: 10.1021/bi00630a010. [DOI] [PubMed] [Google Scholar]
  4. Gellert M. DNA topoisomerases. Annu Rev Biochem. 1981;50:879–910. doi: 10.1146/annurev.bi.50.070181.004311. [DOI] [PubMed] [Google Scholar]
  5. Greene P. J., Heyneker H. L., Bolivar F., Rodriguez R. L., Betlach M. C., Covarrubias A. A., Backman K., Russel D. J., Tait R., Boyer H. W. A general method for the purification of restriction enzymes. Nucleic Acids Res. 1978 Jul;5(7):2373–2380. doi: 10.1093/nar/5.7.2373. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Hardies S. C., Patient R. K., Klein R. D., Ho F., Reznikoff W. S., Wells R. D. Construction and mapping of recombinant plasmids used for the preparation of DNA fragments containing the Escherichia coli lactose operator and promoter. J Biol Chem. 1979 Jun 25;254(12):5527–5534. [PubMed] [Google Scholar]
  7. Ivanov V. I., Minyat E. E. The transitions between left- and right-handed forms of poly(dG-dC). Nucleic Acids Res. 1981 Sep 25;9(18):4783–4798. doi: 10.1093/nar/9.18.4783. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Kłysik J., Stirdivant S. M., Larson J. E., Hart P. A., Wells R. D. Left-handed DNA in restriction fragments and a recombinant plasmid. Nature. 1981 Apr 23;290(5808):672–677. doi: 10.1038/290672a0. [DOI] [PubMed] [Google Scholar]
  9. Kłysik J., Stirdivant S. M., Wells R. D. Left-handed DNA. Cloning, characterization, and instability of inserts containing different lengths of (dC-dG) in Escherichia coli. J Biol Chem. 1982 Sep 10;257(17):10152–10158. [PubMed] [Google Scholar]
  10. Lilley D. M. The inverted repeat as a recognizable structural feature in supercoiled DNA molecules. Proc Natl Acad Sci U S A. 1980 Nov;77(11):6468–6472. doi: 10.1073/pnas.77.11.6468. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Panayotatos N., Wells R. D. Cruciform structures in supercoiled DNA. Nature. 1981 Feb 5;289(5797):466–470. doi: 10.1038/289466a0. [DOI] [PubMed] [Google Scholar]
  12. Peck L. J., Nordheim A., Rich A., Wang J. C. Flipping of cloned d(pCpG)n.d(pCpG)n DNA sequences from right- to left-handed helical structure by salt, Co(III), or negative supercoiling. Proc Natl Acad Sci U S A. 1982 Aug;79(15):4560–4564. doi: 10.1073/pnas.79.15.4560. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Pulleyblank D. E., Shure M., Tang D., Vinograd J., Vosberg H. P. Action of nicking-closing enzyme on supercoiled and nonsupercoiled closed circular DNA: formation of a Boltzmann distribution of topological isomers. Proc Natl Acad Sci U S A. 1975 Nov;72(11):4280–4284. doi: 10.1073/pnas.72.11.4280. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Singleton C. K., Klysik J., Stirdivant S. M., Wells R. D. Left-handed Z-DNA is induced by supercoiling in physiological ionic conditions. Nature. 1982 Sep 23;299(5881):312–316. doi: 10.1038/299312a0. [DOI] [PubMed] [Google Scholar]
  15. Singleton C. K., Wells R. D. The facile generation of covalently closed, circular DNAs with defined negative superhelical densities. Anal Biochem. 1982 May 15;122(2):253–257. doi: 10.1016/0003-2697(82)90277-9. [DOI] [PubMed] [Google Scholar]
  16. Stirdivant S. M., Kłysik J., Wells R. D. Energetic and structural inter-relationship between DNA supercoiling and the right- to left-handed Z helix transitions in recombinant plasmids. J Biol Chem. 1982 Sep 10;257(17):10159–10165. [PubMed] [Google Scholar]
  17. Wartell R. M., Klysik J., Hillen W., Wells R. D. Junction between Z and B conformations in a DNA restriction fragment: evaluation by Raman spectroscopy. Proc Natl Acad Sci U S A. 1982 Apr;79(8):2549–2553. doi: 10.1073/pnas.79.8.2549. [DOI] [PMC free article] [PubMed] [Google Scholar]

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