title: Statistical mechanics of supercoils and the torsional stiffness of the DNA 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.
mesh_terms: D004278:DNA, Superhelical; D009010:Monte Carlo Method; D009690:Nucleic Acid Conformation
chemical_list: D004278:DNA, Superhelical