TitleChromosome organization shapes replisome dynamics in Caulobacter crescentus.
Publication TypeJournal Article
Year of Publication2024
AuthorsZhang C, Joseph AMary, Casini L, Collier J, Badrinarayanan A, Manley S
JournalNat Commun
Date Published2024 Apr 24
KeywordsBacterial Proteins, Caulobacter crescentus, Chromosome Segregation, Chromosomes, Bacterial, DNA Replication, DNA, Bacterial

DNA replication in bacteria takes place on highly compacted chromosomes, where segregation, transcription, and repair must occur simultaneously. Within this dynamic environment, colocalization of sister replisomes has been observed in many bacterial species, driving the hypothesis that a physical linker may tether them together. However, replisome splitting has also been reported in many of the same species, leaving the principles behind replisome organization a long-standing puzzle. Here, by tracking the replisome β-clamp subunit in live Caulobacter crescentus, we find that rapid DNA segregation can give rise to a second focus which resembles a replisome, but does not replicate DNA. Sister replisomes can remain colocalized, or split apart to travel along DNA separately upon disruption of chromosome inter-arm alignment. Furthermore, chromosome arm-specific replication-transcription conflicts differentially modify replication speed on the two arms, facilitate the decoupling of the two replisomes. With these observations, we conclude that the dynamic chromosome organization flexibly shapes the organization of sister replisomes, and we outline principles which can help to reconcile previously conflicting models of replisome architecture.

Alternate JournalNat Commun
PubMed ID38658616
PubMed Central ID438963
Grant List819823 Piko / / EC | EU Framework Programme for Research and Innovation H2020 | H2020 Priority Excellent Science | H2020 European Research Council (H2020 Excellent Science - European Research Council) /