Left-handed Z-DNA is induced by supercoiling in physiological ionic conditions

Nature. 1982 Sep 23;299(5881):312-6. doi: 10.1038/299312a0.

Abstract

In physiological ionic conditions (200 mM NaCl), the (dC-dG)16 and (dC-dG)13 blocks in plasmid pRW751 are in a left-handed state when the negative superhelical density of the plasmid is greater than 0.972. As the salt concentration decreases or when (dmC-dG) sequences are present, less negative supercoiling is required to induce the right- to left-handed DNA transition. Furthermore, the single strand-specific nuclease, S1, recognizes and cleaves aberrant structural features at the junction between neighbouring right- and left-handed DNA regions.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • DNA, Superhelical*
  • Electrophoresis, Agar Gel
  • Endonucleases
  • Escherichia coli / genetics
  • Ethidium
  • Methylation
  • Models, Theoretical
  • Nucleic Acid Conformation*
  • Plasmids
  • Single-Strand Specific DNA and RNA Endonucleases
  • Sodium Chloride

Substances

  • DNA, Superhelical
  • Sodium Chloride
  • Endonucleases
  • Single-Strand Specific DNA and RNA Endonucleases
  • Ethidium