title: UvrD-dependent replication of rolling-circle plasmids in Escherichia coli.
abstract: The Escherichia coli UvrD helicase (or helicase II) is known for its involvement in DNA repair. We report that UvrD is required for DNA replication of several different rolling-circle plasmids in E. coli, whereas its homologue, the Rep helicase, is not. Lack of UvrD helicase does not impair the first step of plasmid replication, nicking of the double-stranded origin by the plasmid initiator protein. However, replication proceeds no further without UvrD. Indeed, the nicked plasmid molecules accumulate to a high level in uvrD mutants. We conclude that UvrD is the replicative helicase of various rolling-circle plasmids. This is the first description of a direct implication of UvrD in DNA replication in vivo.
authors.affiliation: Laboratoire de G¿en¿etique Microbienne, INRA, Domaine de Vilvert, 78352 Jouy-en-Josas cedex, France. bruand@biotec.jouy.inra.fr
authors.forename: C
authors.initials: C
authors.lastname: Bruand
authors.forename: S D
authors.initials: SD
authors.lastname: Ehrlich
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D004265:DNA Helicases / Q000378:metabolism*; D004261:DNA Replication; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins; D009154:Mutation; D010957:Plasmids; D018741:Replication Origin
chemical_list: D029968:Escherichia coli Proteins; C506744:rep protein, E coli; D000251:Adenosine Triphosphatases; C506746:UvrD protein, E coli; D004265:DNA Helicases