Human white blood cells contain cyclobutyl pyrimidine dimer photolyase.
Although enzymatic photoreactivation of cyclobutyl pyrimidine dimers in DNA is present in almost all organisms, its presence in placental mammals is controversial. We tested human white blood cells for photolyase by using three defined DNAs (supercoiled pET-2, nonsupercoiled bacteriophage lambda, and a defined-sequence 287-bp oligonucleotide), two dimer-specific endonucleases (T4 endonuclease V and UV endonuclease from Micrococcus luteus), and three assay methods. We show that human white blood cells contain photolyase that can photorepair pyrimidine dimers in defined supercoiled and linear DNAs and in a 287-bp oligonucleotide and that human photolyase is active on genomic DNA in intact human cells.
Sutherland
B M
BM
Biology Department, Brookhaven National Laboratory, Upton, NY 11973-5000, USA.
Bennett
P V
PV
D010582:Bacteriophage lambda; D001483:Base Sequence; D004260:DNA Repair / Q000528:radiation effects; D004278:DNA, Superhelical / Q000378:metabolism; D004279:DNA, Viral / Q000378:metabolism; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000302:isolation & purification*; D006801:Humans; D007962:Leukocytes / Q000201:enzymology* / Q000528:radiation effects; D008027:Light; D008969:Molecular Sequence Data; D011740:Pyrimidine Dimers / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism
D004278:DNA, Superhelical; D004279:DNA, Viral; D011740:Pyrimidine Dimers; D004255:Deoxyribodipyrimidine Photo-Lyase