title: RecA-promoted, RecFOR-independent progressive disassembly of replisomes stalled by helicase inactivation.
abstract: In all organisms, replication impairment is a recognized source of genomic instability, raising an increasing interest in the fate of inactivated replication forks. We used Escherichia coli strains with a temperature-inactivated replicative helicase (DnaB) and in vivo single-molecule microscopy to quantify the detailed molecular processing of stalled replication forks. After helicase inactivation, RecA binds to blocked replication forks and is essential for the rapid release of hPol III. The entire holoenzyme is disrupted little by little, with some components lost in few minutes, while others are stable in 70% of cells for at least 1 hr. Although replisome dissociation is delayed in a recA mutant, it is not affected by RecF or RecO inactivation. RecFOR are required for full RecA filaments formation, and we propose that polymerase clearance can be catalyzed by short, RecFOR-independent RecA filaments. Our results identify a function for the universally conserved, central recombination protein RecA.
authors.affiliation: CNRS, Centre de Génétique Moléculaire, UPR3404, Gif-sur-Yvette 91198, France. lia@cgm.cnrs-gif.fr
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lia
authors.forename: Annafrancesca
authors.initials: A
authors.lastname: Rigato
authors.forename: Emilie
authors.initials: E
authors.lastname: Long
authors.forename: Carine
authors.initials: C
authors.lastname: Chagneau
authors.forename: Marie
authors.initials: M
authors.lastname: Le Masson
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Allemand
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Michel
mesh_terms: D004258:DNA Polymerase III / Q000378:metabolism; D004261:DNA Replication; D004269:DNA, Bacterial / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D053488:DnaB Helicases / Q000378:metabolism*; D004789:Enzyme Activation; D004926:Escherichia coli / Q000166:cytology* / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D005453:Fluorescence; D020035:Holoenzymes / Q000378:metabolism; D008164:Luminescent Proteins / Q000378:metabolism; D009097:Multienzyme Complexes / Q000378:metabolism*; D011485:Protein Binding; D011938:Rec A Recombinases / Q000378:metabolism*; D013696:Temperature; D000099272:Replisomes
chemical_list: D004258:DNA Polymerase III; D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D004259:DNA-Directed DNA Polymerase; D053488:DnaB Helicases; D029968:Escherichia coli Proteins; D020035:Holoenzymes; D008164:Luminescent Proteins; D009097:Multienzyme Complexes; D011938:Rec A Recombinases; D000099272:Replisomes; C506730:dnaB protein, E coli