Recognition of the ring-opened state of proliferating cell nuclear antigen by replication factor C promotes eukaryotic clamp-loading.

ABSTRACT: Proliferating cell nuclear antigen (PCNA, sliding clamp) is a toroidal-shaped protein that encircles DNA and plays a pivotal role in DNA replication, modification and repair. To perform its vital functions, the clamp has to be opened and resealed at primer-template junctions by a clamp loader molecular machine, replication factor C (RFC). The mechanism of this process constitutes a significant piece in the puzzle of processive DNA replication. We show that upon clamp opening the RFC/PCNA complex undergoes a large conformational rearrangement, leading to the formation of an extended interface between the clamp and RFC. Binding of ring-open PCNA to all five RFC subunits transforms the free-energy landscape underlying the closed- to open state transition, trapping PCNA in an open conformation

SUBMITTER: Tainer JA 

PROVIDER: S-EPMC2876781 | biostudies-literature | 2010 Jun

REPOSITORIES: biostudies-literature