title: Condensation of circular DNA.
abstract: A simple model of a circularly closed double-stranded DNA in a poor solvent is considered as an example of a semi-flexible polymer with self-attraction. To find the ground states, the conformational energy is computed as a sum of the bending and torsional elastic components and the effective self-attraction energy. The model includes a relative orientation or sequence dependence of the effective attraction forces between different pieces of the polymer chain. Two series of conformations are analysed: a multicovered circle (a toroid) and a multifold two-headed racquet. The results are presented as a diagram of state. It is suggested that the stability of particular conformations may be controlled by proper adjustment of the primary structure. Application of the model to other semi-flexible polymers is considered.
authors: Department of Civil, Environmental and Geomatic Engineering, University College London, London, United Kingdom. e.starostin@ucl.ac.uk
authors: E L
authors: EL
authors: Starostin
mesh_terms: D004270:DNA, Circular / Q000138:chemical synthesis* / Q000737:chemistry; D011108:Polymers / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D004270:DNA, Circular; D011108:Polymers