The isolation and genetic characteristics of lambda transducing phages of the uvrA + and uvrC + genes of E. coli K12

Abstract

Lambda transducing phages carying the excision repair genes uvrA ⁺ and uvrC ⁺ were selected from a pool of λ phages carrying EcoR1 fragments of E. coli DNA. These phages and also λuvrB ⁺ (obtained from Gottesman) were used to make lysogens of excision-defective strains carrying uvrA ^-, uvrB ^- or uvrC ^-. Lambda uvrA ⁺ was found to transduce strains carrying uvrA ^- but not those carrying uvrB ^- or uvrC ^-, to normal ultraviolet resistance. Similarly, λuvrB ⁺ and λuvrC ⁺ were found to complement only the corresponding uvr ^- allele. The λ transducing phages were co-transduced with gal ⁺ by P1 phage into lysogenic gal^- recipients, and presumably were integrated at the normal prophage site.