Escherichia coli DNA photolyase reverses cyclobutane pyrimidine dimers but not pyrimidine-pyrimidone (6-4) photoproducts.
The effect of purified Escherichia coli DNA photolyase on the UV light-induced pyrimidine-pyrimidone (6-4) photoproduct and cyclobutane pyrimidine dimer was investigated in vitro using enzyme purified from cells carrying the cloned phr gene (map position, 15.7 min). Photoproducts were examined both as site-specific lesions in end-labeled DNA and as chromatographically identified products in uniformly labeled DNA. E. coli DNA photolyase removed cyclobutane dimers but had no activity on pyrimidine-pyrimidone (6-4) photoproducts. Photoreactivation can therefore be used to separate the biological effects of these two UV light-induced molecular lesions.
D002851:Chromatography, High Pressure Liquid; D003503:Cyclobutanes / Q000032:analysis*; D004247:DNA / Q000528:radiation effects*; D004260:DNA Repair; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000494:pharmacology*; D004926:Escherichia coli / Q000201:enzymology*; D008190:Lyases / Q000494:pharmacology*; D010777:Photochemistry; D011743:Pyrimidines / Q000032:analysis*; D011744:Pyrimidinones / Q000032:analysis*; D014466:Ultraviolet Rays
D003503:Cyclobutanes; D011743:Pyrimidines; D011744:Pyrimidinones; D004247:DNA; D008190:Lyases; D004255:Deoxyribodipyrimidine Photo-Lyase