Single-molecule live cell imaging of Rep reveals the dynamic interplay between an accessory replicative helicase and the replisome.

ABSTRACT: DNA replication must cope with nucleoprotein barriers that impair efficient replisome translocation. Biochemical and genetic studies indicate accessory helicases play essential roles in replication in the presence of nucleoprotein barriers, but how they operate inside the cell is unclear. With high-speed single-molecule microscopy we observed genomically-encoded fluorescent constructs of the accessory helicase Rep and core replisome protein DnaQ in live Escherichia coli cells. We demonstrate that Rep colocalizes with 70% of replication forks, with a hexameric stoichiometry, indicating maximal occupancy of the single DnaB hexamer. Rep associates dynamically with the replisome with an average dwell time of 6.5 ms dependent on ATP hydrolysis, indicating rapid binding then translocation away f

SUBMITTER: Syeda AH 

PROVIDER: S-EPMC6614839 | biostudies-literature | 2019 Jul

REPOSITORIES: biostudies-literature