Poly(dG)-poly(dC) DNA appears shorter than poly(dA)-poly(dT) and possibly adopts an A-related conformation on a mica surface under ambient conditions

FEBS Lett. 2007 Dec 22;581(30):5843-6. doi: 10.1016/j.febslet.2007.11.058. Epub 2007 Nov 29.

Abstract

Three types of DNA: approximately 2700 bp polydeoxyguanylic olydeoxycytidylic acid [poly(dG)-poly(dC)], approximately 2700 bp polydeoxyadenylic polydeoxythymidylic acid [poly(dA)-poly(dT)] and 2686 bp linear plasmid pUC19 were deposited on a mica surface and imaged by atomic force microscopy. Contour length measurements show that the average length of poly(dG)-poly(dC) is approximately 30% shorter than that of poly(dA)-poly(dT) and the plasmid. This led us to suggest that individual poly(dG)-poly(dC) molecules are immobilized on mica under ambient conditions in a form which is likely related to the A-form of DNA in contrast to poly(dA)-poly(dT) and random sequence DNA which are immobilized in a form that is related to the DNA B-form.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aluminum Silicates / chemistry*
  • DNA, A-Form / chemistry*
  • Microscopy, Atomic Force
  • Nucleic Acid Conformation*
  • Plasmids / ultrastructure
  • Poly dA-dT / chemistry*
  • Polydeoxyribonucleotides / chemistry*

Substances

  • Aluminum Silicates
  • DNA, A-Form
  • Polydeoxyribonucleotides
  • Poly dA-dT
  • poly(dC-dG)
  • mica