Affordable Access

[Conformational effects of DNA stretching].

Authors
  • Mazur, J
  • Jernigan, R L
  • Sarai, A
Type
Published Article
Journal
Molekuliarnaia biologiia
Publication Date
Jan 01, 2003
Volume
37
Issue
2
Pages
277–287
Identifiers
PMID: 12723475
Source
Medline
License
Unknown

Abstract

DNA is an extensible molecule, and an extended conformation of DNA is involved in some biological processes. We have examined the effect of elongation stress on the conformational properties of DNA base pairs by conformational analysis. The calculations show that stretching does significantly affect the conformational properties and flexibilities of base pairs. In particular, we have found that the propeller twist in base pairs reverses its sign upon stretching. The energy profile analysis indicates that electrostatic interactions make a major contribution to the stabilization of the positive-propeller-twist configuration in stretched DNA. This stretching also results in a monotonic decrease in the helical twist angle, tending to unwind the double helix. Fluctuations in most variables initially increase upon stretching, because of unstacking of base pairs, but then the fluctuations decrease as DNA is stretched further, owing to the formation of specific interactions between base pairs induced by the positive propeller twist. Thus, the stretching of DNA has particularly significant effects upon DNA flexibility. These changes in both the conformation and flexibility of base pairs probably have a role in functional interactions with proteins.

Report this publication

Statistics

Seen <100 times