title: Recombinant levels of Escherichia coli K-12 mutants deficient in various replication, recombination, or repair genes.
abstract: Escherichia coli strains containing mutations in lexA, rep, uvrA, uvrD, uvrE, lig, polA, dam, or xthA were constructed and tested for conjugation and transduction proficiencies and ability to form Lac+ recombinants in an assay system utilizing a nontandem duplication of two partially deleted lactose operons (lacMS286phi80dIIlacBK1). lexA and rep mutants were as deficient (20% of wild type) as recB and recC strains in their ability to produce Lac+ progeny. All the other strains exhibited increased frequencies of Lac+ recombinant formation, compared with wild type, ranging from 2- to 13-fold. Some strains showed markedly increased conjugation proficiency (dam uvrD) compared to wild type, while others appeared deficient (polA107). Some differences in transduction proficiency were also observed. Analysis of the Lac+ recombinants formed by the various mutants indicated that they were identical to the recombinants formed by a wild-type strain. The results indicate that genetic recombination in E. coli is a highly regulated process involving multiple gene products.
mesh_terms: D004260:DNA Repair; D004261:DNA Replication; D004269:DNA, Bacterial / Q000096:biosynthesis / Q000528:radiation effects; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism / Q000528:radiation effects; D005796:Genes; D007785:Lactose / Q000096:biosynthesis; D009154:Mutation; D011995:Recombination, Genetic; D014466:Ultraviolet Rays
chemical_list: D004269:DNA, Bacterial; D007785:Lactose