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Lookup NU author(s): Dr Adam WollmanORCiD
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© Beattie et al. The replisome is a multiprotein machine that carries out DNA replication. In Escherichia coli, a single pair of replisomes is responsible for duplicating the entire 4.6 Mbp circular chromosome. In vitro studies of reconstituted E. coli replisomes have attributed this remarkable processivity to the high stability of the replisome once assembled on DNA. By examining replisomes in live E. coli with fluorescence microscopy, we found that the Pol III* subassembly frequently disengages from the replisome during DNA synthesis and exchanges with free copies from solution. In contrast, the DnaB helicase associates stably with the replication fork, providing the molecular basis for how the E. coli replisome can maintain high processivity and yet possess the flexibility to bypass obstructions in template DNA. Our data challenges the widely-accepted semidiscontinuous model of chromosomal replication, instead supporting a fully discontinuous mechanism in which synthesis of both leading and lagging strands is frequently interrupted.
Author(s): Beattie TR, Kapadia N, Nicolas E, Uphoff S, Wollman AJM, Leake MC, Reyes-Lamothe R
Publication type: Article
Publication status: Published
Online publication date: 31/03/2017
Acceptance date: 28/03/2017
Date deposited: 10/02/2020
ISSN (electronic): 2050-084X
Publisher: eLife Sciences Publications Ltd
PubMed id: 28362256
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