1. A Primase-Induced Conformational Switch Controls the Stability of the Bacterial Replisome.
- Author
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Monachino E, Jergic S, Lewis JS, Xu ZQ, Lo ATY, O'Shea VL, Berger JM, Dixon NE, and van Oijen AM
- Subjects
- DNA Primase genetics, DNA, Bacterial, DNA-Directed DNA Polymerase genetics, DnaB Helicases genetics, Escherichia coli genetics, Escherichia coli Proteins genetics, Holoenzymes genetics, Holoenzymes metabolism, Molecular Conformation, Protein Binding, Protein Conformation, DNA Primase metabolism, DNA Replication, DNA-Directed DNA Polymerase metabolism, DnaB Helicases metabolism, Escherichia coli enzymology, Escherichia coli Proteins metabolism, Holoenzymes chemistry
- Abstract
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 500-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., Competing Interests: Declaration of Interests The authors declare no competing interests., (Copyright © 2020 Elsevier Inc. All rights reserved.)
- Published
- 2020
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