[Dynamic superhelicity in vivo and in vitro]

As it was shown in studies of J. Dubochet using the recently developed method of three-dimensional cryo-microscopy, the interaction of RNA polymerase with plasmid gives rise to a superhelical structure. In this process, two RNA polymerase molecules are located at opposite ends of the plasmid at the tops of the superhelix. The dynamic features of this process are considered, which may be only one of many similar processes, in which energy dissipation during the directed movement of DNA is reduced to a minimum. It is assumed that, upon screwing of two double helices into each other, a three- dimensional mechanical transmission is formed, owing to the spatial features of the double helices comprising the superhelix, which further facilitates this twisting process.