Bacterial replisomes are dynamic multiprotein DNA replication machines that are inherently difficult for structural studies. However, breakthroughs continue to come. The structures of Escherichia coli DNA polymerase III (core)–clamp–DNA subcomplexes solved by single-particle cryo-electron microscopy in both polymerization and proofreading modes and the discovery of the stochastic nature of the bacterial replisomes represent notable progress. The structures reveal an intricate interaction network in the polymerase–clamp subassembly, providing insights on how replisomes may work. Meantime, ensemble and single-molecule functional assays and fluorescence microscopy show that the bacterial replisomes can work in a decoupled and uncoordinated way, with polymerases quickly exchanging and both leading-strand and lagging-strand polymerases and the helicase working independently, contradictory to the elegant textbook view of a highly coordinated machine.
Bibliographical noteKAUST Repository Item: Exported on 2022-06-09
Acknowledged KAUST grant number(s): OSR-2015-CRG4-2644
Acknowledgements: The authors thank Slobodan Jergic, Jacob Lewis, Lisanne Spenkelink, Samir Hamdan and Antoine van Oijen for lively discussions. This work was supported in part by the Australian Research Council (DP150100956 and DP180100858) and King Abdullah University of Science and Technology, Saudi Arabia (OSR-2015-CRG4-2644).
This publication acknowledges KAUST support, but has no KAUST affiliated authors.