Large terminase conformational change induced by connector binding in bacteriophage T7.

ABSTRACT: During bacteriophage morphogenesis DNA is translocated into a preformed prohead by the complex formed by the portal protein, or connector, plus the terminase, which are located at an especial prohead vertex. The terminase is a powerful motor that converts ATP hydrolysis into mechanical movement of the DNA. Here, we have determined the structure of the T7 large terminase by electron microscopy. The five terminase subunits assemble in a toroid that encloses a channel wide enough to accommodate dsDNA. The structure of the complete connector-terminase complex is also reported, revealing the coupling between the terminase and the connector forming a continuous channel. The structure of the terminase assembled into the complex showed a different conformation when compared with the isolated termi

SUBMITTER: Dauden MI 

PROVIDER: S-EPMC3675631 | biostudies-literature | 2013 Jun

REPOSITORIES: biostudies-literature