Simulating the electrostatic guidance of the vectorial translocations in hexameric helicases and translocases.

ABSTRACT: The molecular origin of the action of helicases is explored, starting with a model built based on the different X-ray structures of the large tumor antigen (LTag) hexameric helicase and a simplified model containing the ionized phosphate backbones of a single-strand DNA. The coupling between the protein structural changes and the translocation process is quantified using an effective electrostatic free-energy surface for the protein/DNA complex. This surface is then used in Langevin dynamics simulations of the time dependence of the translocation process. Remarkably, the simulated motion along the free-energy surface results in a vectorial translocation of the DNA, consistent with the biological process. The electrostatic energy of the system appears to reproduce the directionality of this

SUBMITTER: Liu H 

PROVIDER: S-EPMC2678657 | biostudies-literature | 2009 May

REPOSITORIES: biostudies-literature