Bacterial replisomes. (December 2018)

• Record Type: Journal Article
• Authors: Xu, Zhi-Qiang; Dixon, Nicholas E
• Is Part Of: Current opinion in structural biology. Volume 53(2018)
• Page Start: 159
• Page End: 168
• Publication Date: 2018-12
• Subjects: Molecular biology -- Periodicals; 570
• DOI: 10.1016/j.sbi.2018.09.006
• Languages: English
• ISSNs: 0959-440X

Abstract

Graphical abstract: Highlights: Cryo-EM structures of Escherichia coli DNA polymerase III complexes. Bacterial polymerases quickly exchange at replication forks. Bacterial replisomes can work in a decoupled and uncoordinated manner. Replisome speed determines fork arrest efficiency in replication termination. Abstract : 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.