DNA photolyase in E. coli

Derivatives of an E. coli plasmid pKY33 are described having specific insertions or deletions that effect or do not effect the phr gene carried in this plasmid. The various plasmids are tested to determine which cause an inhibition of UV mutagenesis producing glutamine tRNA ochre suppressor mutations. The inhibition is found to require a functional phr gene, which substantiates our earlier report that amplified DNa photolyase interferes specifically with a category of mutagenesis involving targetin gby a pyrimidine dimer. (author). 7 refs.; 1 fig