Ultraviolet radiation damage in DNA

This paper reviews the nature of the radiation damage produced in DNA by the direct absorption of UV photons. Special reference is made to the environmental impact of increased levels of UVB radiation in the biosphere resulting from depletion of the ozone layer. The main focus is on the structural identity and detection of the intramolecular photoproducts derived from the purine and pyrimidine nucleobases in DNA. The role of repair enzymes in removing these photoproducts from DNA is also discussed in connection with their use as probes for locating specific lesions by gel sequencing methods. (author)