The why and how of DNA unlinking

Nucleic Acids Res. 2009 Feb;37(3):661-71. doi: 10.1093/nar/gkp041.


The nucleotide sequence of DNA is the repository of hereditary information. Yet, it is now clear that the DNA itself plays an active role in regulating the ability of the cell to extract its information. Basic biological processes, including control of gene transcription, faithful DNA replication and segregation, maintenance of the genome and cellular differentiation are subject to the conformational and topological properties of DNA in addition to the regulation imparted by the sequence itself. How do these DNA features manifest such striking effects and how does the cell regulate them? In this review, we describe how misregulation of DNA topology can lead to cellular dysfunction. We then address how cells prevent these topological problems. We close with a discussion on recent theoretical advances indicating that the topological problems, themselves, can provide the cues necessary for their resolution by type-2 topoisomerases.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • DNA / chemistry*
  • DNA / metabolism
  • DNA Topoisomerases, Type II / metabolism*
  • Models, Molecular
  • Nucleic Acid Conformation


  • DNA
  • DNA Topoisomerases, Type II