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Journal ArticleDOI

Statistical mechanics of supercoils and the torsional stiffness of the DNA double helix

TLDR
The distribution of closed unknotted polymer chains over the writhing number is calculated by the Monte-Carlo method and the balance which arises from fluctuations in DNA twisting makes it possible to estimate the torsional stiffness of the double helix.
Abstract
The distribution of closed unknotted polymer chains over the writhing number is calculated by the Monte-Carlo method For circular duplex DNA the variance of the distribution equals approximately half the observed variance of equilibrium distribution over the linking number The balance which arises from fluctuations in DNA twisting makes it possible to estimate the torsional stiffness of the double helix

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Citations
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Journal ArticleDOI

Energetics of DNA twisting: I. Relation between twist and cyclization probability*

TL;DR: In this paper, a series of 12 DNA molecules has been studied, which range in length from 237 to 254 bp with a period of about 10 bp, and it was shown that the DNA twisting potential is symmetric.
Journal ArticleDOI

Structure of plectonemically supercoiled DNA

TL;DR: The data suggest that DNA has a branched plectonemic (interwound) form over the range of supercoiling tested, and the relationship between DNA flexibility constants for twisting and bending calculated using the structural data is similar to that deduced from previous studies.
Journal ArticleDOI

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

TL;DR: 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.
Journal ArticleDOI

Torsional rigidity of DNA and length dependence of the free energy of DNA supercoiling.

TL;DR: By analyzing the Boltzmann populations of DNA topoisomers that differ only in their linking numbers, the dependence of the free energy delta G tau of DNA supercoiling on the linking number alpha has been determined for DNA rings as small as 200 base-pairs in length.
Journal ArticleDOI

Statistical mechanics of supercoiled DNA

TL;DR: In this paper, the authors constructed an analytic theory for the plectonemic supercoiling of DNA loops using methods from polymer statistical mechanics, and showed that for fractional linking number perturbations ∣σ∣ 0.02, the supercoils are stable, but thermal fluctuations continue to play an important role, competing with bending and twisting elastic energy.
References
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Book

Theory of elasticity

TL;DR: The equilibrium of rods and plates Elastic waves Dislocations Thermal conduction and viscosity in solids Mechanics of liquid crystals Index as discussed by the authors The equilibrium of rod and plate elastic waves Elastic waves
Journal ArticleDOI

The writhing number of a space curve

TL;DR: This study originated in response to questions that arise in the study of supercoiled double-stranded DNA rings, and measures the extent to which coiling of the central curve has relieved local twisting of the cord.
Journal ArticleDOI

Conformational fluctuations of DNA helix

TL;DR: The distributions in alpha for several DNAs, covalently closed at different temperatures, have been determined and the results have been interpreted in terms of thermal fluctuations of the DNA helix.
Journal ArticleDOI

Flexibility of DNA.

TL;DR: A model for the flexibility of DNA is proposed that is based on discrete variations in the direction of propagation in going from one subunit to the next, which gives a Gaussian distribution function.
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