Coupling of intramolecular and intermolecular linkage complexity of two DNAs

John F. Marko*

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

22 Scopus citations


The free energy of two interlinked circular DNAs is argued to couple their interlinkage (catenation) to their “internal” double-helix linkages. Changes in internal linkage which drive supercoiling can therefore alter the free-energy cost of intermolecule catenations. This effect is weak for low amounts of supercoiling or catenation, but becomes strong when there is more than one link added per persistence length. DNA supercoiling can therefore increase the free-energy cost of interlinkages, and in living cells can help to direct type-II topoisomerases to remove catenations between DNAs following their replication, a process required for the segregation of the duplicate molecules. The related problem of the interaction of applied tension with catenation and supercoiling is also analyzed.

Original languageEnglish (US)
Pages (from-to)900-912
Number of pages13
JournalPhysical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics
Issue number1
StatePublished - 1999

ASJC Scopus subject areas

  • Statistical and Nonlinear Physics
  • Statistics and Probability
  • Condensed Matter Physics


Dive into the research topics of 'Coupling of intramolecular and intermolecular linkage complexity of two DNAs'. Together they form a unique fingerprint.

Cite this