Molecular Mechanisms for Repair of DNA: Part B

The excision-repair of ultraviolet-induced lesions in DNA involves a recogni- tion and incision step which is followed by excision of the damaged material, DNA repair resynthesis, and sealing of the fmal gap by polynucleotide ligase (e.g. Howard-Flanders, 1968). The initial incision step appears to require an endo- nuclease which is absent in the uvrA and uvrR mutants of E. eoli K12 (Braun et al., Part A of this book). The polAl strains are deficient in DNA polymerase I activity (de Lucia a...