Some properties of excision-defective recombination-deficient mutants of Escherichia coli K-12.

Strains of Escherichia coli that carry the mutation uvrA6 show no measurable excision of pyrimidine dimers and are easily killed by ultraviolet (UV) light, whereas strains that carry recA13 are defective in genetic recombination and are also UV-sensitive. An Hfr strain carrying uvrA6 was crossed with an F(-) strain carrying recA13. Among the recombinants… (More)