RT Journal Article
SR Electronic
T1 A Primase-Induced Conformational Switch Controls the Stability of the Bacterial Replisome
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 469312
DO 10.1101/469312
A1 Enrico Monachino
A1 Slobodan Jergic
A1 Jacob S. Lewis
A1 Zhi-Qiang Xu
A1 Allen T.Y. Lo
A1 Valerie L. O’Shea
A1 James M. Berger
A1 Nicholas E. Dixon
A1 Antoine M. van Oijen
YR 2018
UL http://biorxiv.org/content/early/2018/11/13/469312.abstract
AB Recent studies of bacterial DNA replication have led to a picture of the replisome as an entity that freely exchanges DNA polymerases and displays intermittent coupling between the helicase and polymerase(s). Challenging the textbook model of the polymerase holoenzyme acting as a stable complex coordinating the replisome, these observations suggest a role of the helicase as the central organizing hub. We show here that the molecular origin of this newly-found plasticity lies in the >400-fold increase in strength of the interaction between the polymerase holoenzyme and the replicative helicase upon association of the primase with the replisome. By combining in vitro ensemble-averaged and single-molecule assays, we demonstrate that this conformational switch operates during replication and promotes recruitment of multiple holoenzymes at the fork. Our observations provide a molecular mechanism for polymerase exchange and offer a revised model for the replication reaction that emphasizes its stochasticity.