Origin of the intrinsic rigidity of DNA

Janine B. Mills, Paul J Hagerman

Research output: Contribution to journalArticle

38 Citations (Scopus)

Abstract

The intrinsic rigidities of DNA and RNA helices are generally thought to arise from some combination of vertical base-stacking interactions and intra-helix phosphate-phosphate charge repulsion; however, the relative contributions of these two types of interaction to helix rigidity have not been quantified. To address this issue, we have measured the rotational decay times of a 'gapped-duplex' DNA molecule possessing a central, single-stranded region, dT24, before and after addition of the free purine base, N6-methyladenine (meA). Upon addition of meA, the bases pair with the T residues, forming a continuous stack within the gap region. Formation of the gapped duplex is accompanied by a nearly 2-fold increase in decay time, to values that are indistinguishable from the full duplex control for monovalent salt concentrations up to 90 mM. These results indicate that at least 90% of the rigidity of the dTn-dAn homopolymer derives from base pair stacking effects, with phosphate-phosphate interactions contributing relatively little to net helix rigidity at moderate salt concentrations.

Original languageEnglish (US)
Pages (from-to)4055-4059
Number of pages5
JournalNucleic Acids Research
Volume32
Issue number13
DOIs
StatePublished - 2004

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Phosphates
DNA
Base Pairing
Salts
RNA

ASJC Scopus subject areas

  • Genetics

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Origin of the intrinsic rigidity of DNA. / Mills, Janine B.; Hagerman, Paul J.

In: Nucleic Acids Research, Vol. 32, No. 13, 2004, p. 4055-4059.

Research output: Contribution to journalArticle

Mills, Janine B. ; Hagerman, Paul J. / Origin of the intrinsic rigidity of DNA. In: Nucleic Acids Research. 2004 ; Vol. 32, No. 13. pp. 4055-4059.
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