Non-mutagenic repair of (6-4)photoproducts by (6-4)photolyase purified from Drosophila melanogaster.

摘要

The (6-4)photoproduct DNA photolyase ((6-4)photolyase) repairs UV-induced pyrimidine (6-4) pyrimidone photoproduct ((6-4)photoproduct, pyr[6,4]pyr) in a light dependent manner. Drosophila (6-4)photolyase was purified to near homogeneity from Drosophila embryonic cells and is shown to be a 62 kDa protein as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The purified (6-4)photolyase repairs (6-4)photoproducts induced at 5'-CC-3' site (C[6,4]C) as well as T[6,4]T and T[6,4]C. Photoreactivation of (6-4)photoproduct constructed in M13 phage eliminates the replication block and abolishes induced mutagenesis in E. coli cells, suggesting that the (6-4)photolyase repairs the photoproduct to the unmodified form.