title: Spontaneous and cisplatin-induced recombination in Escherichia coli.
abstract: To measure cisplatin (cis-diaminodichloroplatinum(II))-induced recombination, we have used a qualitative intrachromosomal assay utilizing duplicate inactive lac operons containing non-overlapping deletions and selection for Lac+ recombinants. The two operons are separated by one Mb and conversion of one of them yields the Lac+ phenotype. Lac+ formation for both spontaneous and cisplatin-induced recombination requires the products of the recA, recBC, ruvA, ruvB, ruvC, priA and polA genes. Inactivation of the recF, recO, recR and recJ genes decreased cisplatin-induced, but not spontaneous, recombination. The dependence on PriA and RecBC suggests that recombination is induced following stalling or collapse of replication forks at DNA lesions to form double strand breaks. The lack of recombination induction by trans-DDP suggests that the recombinogenic lesions for cisplatin are purine-purine intrastrand crosslinks.
authors.affiliation: Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, 364 Plantation Street, LRB823 Worcester, MA 01655, USA.
authors.forename: Anetta
authors.initials: A
authors.lastname: Nowosielska
authors.forename: Melissa A
authors.initials: MA
authors.lastname: Calmann
authors.forename: Zoran
authors.initials: Z
authors.lastname: Zdraveski
authors.forename: John M
authors.initials: JM
authors.lastname: Essigmann
authors.forename: M G
authors.initials: MG
authors.lastname: Marinus
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D002945:Cisplatin / Q000494:pharmacology*; D003432:Cross-Linking Reagents / Q000494:pharmacology*; D004260:DNA Repair / Q000187:drug effects; D004269:DNA, Bacterial / Q000187:drug effects; D004926:Escherichia coli / Q000235:genetics*; D029968:Escherichia coli Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D020868:Gene Silencing / Q000187:drug effects; D005798:Genes, Bacterial; D007763:Lac Operon / Q000187:drug effects; D008957:Models, Genetic; D011995:Recombination, Genetic / Q000187:drug effects*
chemical_list: D003432:Cross-Linking Reagents; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D002945:Cisplatin