Micromechanics of Single Supercoiled Dna Molecules
نویسنده
چکیده
The theory of the mechanical response of single DNA molecules under stretching and twisting stresses is reviewed. Using established results for the the semiflexible polymer including the effect of torsional stress, and for the free energy of plectonemic supercoils, a theory of coexisting plectonemic and extended DNA is constructed and shown to produce phenomena observed experimentally. Analytical results for DNA extension and torque are presented, and effects of anharmonicities in the plectonemic free energy are described. An application of the theory to the problem of torsional-stress-induced cruciform extrusion is also discussed.
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