Energy landscape for DNA rotation and sliding through a phage portal.

ABSTRACT: Molecular motors involved in the packaging of DNA in tailed viruses are among the strongest known. The mechanism by which the motors operate has long been speculated to involve a coupling between rotation of the portal pore (the gate through which DNA passes upon its packaging or ejection), and translation of DNA. Recent experimental evidence rules out portal rotation with a substantial degree of certainty. We have created an atomistic model for the interaction between DNA and the portal of the bacteriophage SPP1, on the basis of cryo-electron microscopy images and of a recently solved crystal structure. A free energy surface describing the interaction is calculated using molecular dynamics simulations, and found to be inconsistent with a mechanism in which portal rotation drives DNA impor

SUBMITTER: Nummela J 

PROVIDER: S-EPMC2717235 | biostudies-literature | 2009 Feb

REPOSITORIES: biostudies-literature