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Proceedings of the National Academy of Sciences of the United States of America logoLink to Proceedings of the National Academy of Sciences of the United States of America
. 1995 Apr 11;92(8):3581–3585. doi: 10.1073/pnas.92.8.3581

A constant radius of curvature model for the organization of DNA in toroidal condensates.

N V Hud 1, K H Downing 1, R Balhorn 1
PMCID: PMC42211  PMID: 7724602

Abstract

Toroidal DNA condensates have received considerable attention for their possible relationship to the packaging of DNA in viruses and in general as a model of ordered DNA condensation. A spool-like model has primarily been supported for DNA organization within toroids. However, our observations suggest that the actual organization may be considerably different. We present an alternate model in which DNA for a given toroid is organized within a series of equally sized contiguous loops that precess about the toroid axis. A related model for the toroid formation process is also presented. This kinetic model predicts a distribution of toroid sizes for DNA condensed from solution that is in good agreement with experimental data.

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Selected References

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  1. Allison S. A., Herr J. C., Schurr J. M. Structure of viral phi 29 DNA condensed by simple triamines: a light-scattering and electron-microscopy study. Biopolymers. 1981 Mar;20(3):469–488. doi: 10.1002/bip.1981.360200305. [DOI] [PubMed] [Google Scholar]
  2. Arscott P. G., Li A. Z., Bloomfield V. A. Condensation of DNA by trivalent cations. 1. Effects of DNA length and topology on the size and shape of condensed particles. Biopolymers. 1990;30(5-6):619–630. doi: 10.1002/bip.360300514. [DOI] [PubMed] [Google Scholar]
  3. Chattoraj D. K., Gosule L. C., Schellman A. DNA condensation with polyamines. II. Electron microscopic studies. J Mol Biol. 1978 May 25;121(3):327–337. doi: 10.1016/0022-2836(78)90367-4. [DOI] [PubMed] [Google Scholar]
  4. Earnshaw W. C., Harrison S. C. DNA arrangement in isometric phage heads. Nature. 1977 Aug 18;268(5621):598–602. doi: 10.1038/268598a0. [DOI] [PubMed] [Google Scholar]
  5. Gosule L. C., Schellman J. A. Compact form of DNA induced by spermidine. Nature. 1976 Jan 29;259(5541):333–335. doi: 10.1038/259333a0. [DOI] [PubMed] [Google Scholar]
  6. Gosule L. C., Schellman J. A. DNA condensation with polyamines I. Spectroscopic studies. J Mol Biol. 1978 May 25;121(3):311–326. doi: 10.1016/0022-2836(78)90366-2. [DOI] [PubMed] [Google Scholar]
  7. Hagerman P. J. Flexibility of DNA. Annu Rev Biophys Biophys Chem. 1988;17:265–286. doi: 10.1146/annurev.bb.17.060188.001405. [DOI] [PubMed] [Google Scholar]
  8. Haynes M., Garrett R. A., Gratzer W. B. Structure of nucleic acid-poly base complexes. Biochemistry. 1970 Oct 27;9(22):4410–4416. doi: 10.1021/bi00824a600. [DOI] [PubMed] [Google Scholar]
  9. Hsiang M. W., Cole R. D. Structure of histone H1-DNA complex: effect of histone H1 on DNA condensation. Proc Natl Acad Sci U S A. 1977 Nov;74(11):4852–4856. doi: 10.1073/pnas.74.11.4852. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Hud N. V., Allen M. J., Downing K. H., Lee J., Balhorn R. Identification of the elemental packing unit of DNA in mammalian sperm cells by atomic force microscopy. Biochem Biophys Res Commun. 1993 Jun 30;193(3):1347–1354. doi: 10.1006/bbrc.1993.1773. [DOI] [PubMed] [Google Scholar]
  11. Klimenko S. M., Tikchonenko T. I., Andreev V. M. Packing of DNA in the head of bacteriophage T2. J Mol Biol. 1967 Feb 14;23(3):523–533. doi: 10.1016/s0022-2836(67)80122-0. [DOI] [PubMed] [Google Scholar]
  12. Manning G. S. Thermodynamic stability theory for DNA doughnut shapes induced by charge neutralization. Biopolymers. 1980 Jan;19(1):37–59. doi: 10.1002/bip.1980.360190104. [DOI] [PubMed] [Google Scholar]
  13. Marx K. A., Reynolds T. C. Spermidine-condensed phi X174 DNA cleavage by micrococcal nuclease: torus cleavage model and evidence for unidirectional circumferential DNA wrapping. Proc Natl Acad Sci U S A. 1982 Nov;79(21):6484–6488. doi: 10.1073/pnas.79.21.6484. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Noll M. Subunit structure of chromatin. Nature. 1974 Sep 20;251(5472):249–251. doi: 10.1038/251249a0. [DOI] [PubMed] [Google Scholar]
  15. Richards K. E., Williams R. C., Calendar R. Mode of DNA packing within bacteriophage heads. J Mol Biol. 1973 Aug 5;78(2):255–259. doi: 10.1016/0022-2836(73)90114-9. [DOI] [PubMed] [Google Scholar]
  16. Shore D., Langowski J., Baldwin R. L. DNA flexibility studied by covalent closure of short fragments into circles. Proc Natl Acad Sci U S A. 1981 Aug;78(8):4833–4837. doi: 10.1073/pnas.78.8.4833. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Widom J., Baldwin R. L. Cation-induced toroidal condensation of DNA studies with Co3+(NH3)6. J Mol Biol. 1980 Dec 25;144(4):431–453. doi: 10.1016/0022-2836(80)90330-7. [DOI] [PubMed] [Google Scholar]
  18. Wilson R. W., Bloomfield V. A. Counterion-induced condesation of deoxyribonucleic acid. a light-scattering study. Biochemistry. 1979 May 29;18(11):2192–2196. doi: 10.1021/bi00578a009. [DOI] [PubMed] [Google Scholar]

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