Supercoiling of DNA plasmids: mechanics of the generalized ply

G. H. M. Van Der Heijden, S. Neukirch, John Michael Tutill Thompson

Research output: Contribution to journalArticle

57 Citations (Scopus)

Abstract

In this paper we address the mechanics of ply formation in DNA supercoils. We extend the variable ply formulation of Coleman & Swigon to include end loads, and the derived constitutive relations of this generalized ply are shown to be in excellent agreement with experiments. We make a careful physical examination of the uniform ply in which two strands coil around one another in the form of a helix. We next address the problem of determining the link (Lk), twist (Tw) and writhe (Wr) of a closed DNA plasmid from an inspection of its electron micrograph. Previous work has made use of the topological relation, Lk = Tw + Wr, but we show how this kinematic result can be augmented by the mechanics solutions. A very precise result is achieved in a trial calculation.

Original languageEnglish
Pages (from-to)959-985
Number of pages26
JournalProceedings of the Royal Society of Edinburgh A
Volume458
Issue number2020
DOIs
Publication statusPublished - Apr 2002

Keywords

  • supercoiling of DNA
  • DNA molecule
  • writhing
  • ply mechanics
  • writhing of DNA
  • electron micrograph
  • rod theory
  • ELASTIC STABILITY
  • CROSS-SECTION
  • SELF-CONTACT
  • RODS
  • CONFIGURATIONS
  • MOLECULE
  • LINKING
  • NUMBER
  • MODEL

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