Thermal denaturation of a helicoidal DNA model

The full text is available at: http://arxiv.org/PS_cache/cond-mat/pdf/0309/0309454v1.pdfThis is also available in Arxiv: http://arxiv.org/abs/cond-mat/0309454Journal URL: http://pre.aps.org/We study the static and dynamical properties of DNA in the vicinity of its melting transition, i.e. the separation of the two strands upon heating. The investigation is based on a simple mechanical model which includes the helicoidal geometry of the molecule and allows an exact numerical evaluation of its thermodynamical properties. Dynamical simulations of long-enough molecular segments allow the study of the structure factors and of the properties of the denaturated regions. Simulations of finite chains display the hallmarks of a first order transition for sufficiently long-ranged stacking forces although a study of the model's ``universality class'' strongly suggests the presence of an ``underlying'' continuous transition