title: Anticipating chromosomal replication fork arrest: SSB targets repair DNA helicases to active forks.
abstract: In bacteria, several salvage responses to DNA replication arrest culminate in reassembly of the replisome on inactivated forks to resume replication. The PriA DNA helicase is a prominent trigger of this replication restart process, preceded in many cases by a repair and/or remodeling of the arrested fork, which can be performed by many specific proteins. The mechanisms that target these rescue effectors to damaged forks in the cell are unknown. We report that the single-stranded DNA binding (SSB) protein is the key factor that links PriA to active chromosomal replication forks in vivo. This targeting mechanism determines the efficiency by which PriA reaches its specific DNA-binding site in vitro and directs replication restart in vivo. The RecG and RecQ DNA helicases, which are involved in intricate replication reactivation pathways, also associate with the chromosomal replication forks by similarly interacting with SSB. These results identify SSB as a platform for linking a 'repair toolbox' with active replication forks, providing a first line of rescue responses to accidental arrest.
authors.affiliation: Unité de Génétique Microbienne, Laboratoire de Genetique Microbienne, INRA, Domaine de Vilvert, Jouy en Josas, France.
authors.forename: François
authors.initials: F
authors.lastname: Lecointe
authors.forename: Céline
authors.initials: C
authors.lastname: Sérèna
authors.forename: Marion
authors.initials: M
authors.lastname: Velten
authors.forename: Audrey
authors.initials: A
authors.lastname: Costes
authors.forename: Stephen
authors.initials: S
authors.lastname: McGovern
authors.forename: Jean-Christophe
authors.initials: JC
authors.lastname: Meile
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Errington
authors.forename: S Dusko
authors.initials: SD
authors.lastname: Ehrlich
authors.forename: Philippe
authors.initials: P
authors.lastname: Noirot
authors.forename: Patrice
authors.initials: P
authors.lastname: Polard
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology* / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002876:Chromosomes, Bacterial / Q000235:genetics / Q000378:metabolism*; D004260:DNA Repair / Q000502:physiology; D004261:DNA Replication / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D053484:RecQ Helicases / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D053484:RecQ Helicases