MODELING SUPERHELICAL DNA - RECENT ANALYTICAL AND DYNAMIC APPROACHES

During the past year, a variety of diverse and complementary approache s have been presented for modeling superhelical DNA, offering new phys ical and biological insights into fundamental functional processes of DNA. Analytical approaches have probed deeper into the effects of entr opy and thermal fluctuations on DNA structure and on various topologic al constraints induced by DNA-binding proteins. In tandem, new kinetic approaches by molecular, Langevin and Brownian dynamics, as well as e xtensions of elastic-rod theory - have begun to offer dynamic informat ion associated with supercoiling. Such dynamic approaches, along with other equilibrium studies, are refining the basic elastic-rod and poly mer framework and incorporating more realistic treatments of salt and sequence-specific features. These collective advances in modeling larg e DNA molecules, in concert with technological innovations, are pointi ng to an exciting interplay between theory and experiment on the horiz on.