Kinking the double helix by bending deformation

Quan Du, Alexander Kotlyar, Alexander Vologodskii

Research output: Contribution to journalArticlepeer-review

94 Scopus citations


DNA bending and torsional deformations that often occur during its functioning inside the cell can cause local disruptions of the regular helical structure. The disruptions created by negative torsional stress have been studied in detail, but those caused by bending stress have only been analyzed theoretically. By probing the structure of very small DNA circles, we determined that bending stress disrupts the regular helical structure when the radius of DNA curvature is smaller than 3.5 nm. First, we developed an efficient method to obtain covalently closed DNA minicircles. To detect structural disruptions in the minicircles we treated them by single-strand-specific endonucleases. The data showed that the regular DNA structure is disrupted by bending deformation in the 64-65-bp minicircles, but not in the 85-86-bp minicircles. Our results suggest that strong DNA bending initiates kink formation while preserving base pairing.

Original languageEnglish (US)
Pages (from-to)1120-1128
Number of pages9
JournalNucleic acids research
Issue number4
StatePublished - Mar 2008
Externally publishedYes

ASJC Scopus subject areas

  • Genetics


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