Action of a nuclease from rat nuclei on UV-irradiated DNA.
An Mg(2+)-dependent nuclease was highly purified from rat-liver nuclei. The nuclease activity was enhanced in ultraviolet light (UV)-irradiated dsDNA, but not in unirradiated dsDNA. Irrespective of UV irradiation, ssDNA was readily cleaved by this enzyme. UV-irradiated plasmid DNA was incubated with this enzyme and subjected to the template primer activity assay with a Klenow polymerase. With increasing incubation time, the activity was enhanced in the circular-relaxed and linear forms, but not in the superhelical form. These results implied that this enzyme excises UV-damaged sites in dsDNA to form single strand gaps for repair synthesis.
Hibino
Y
Y
Cell Biology Division, Faculty of Pharmaceutical Sciences, Toyama Medical & Pharmaceutical University, Japan.
Nomura
Y
Y
Iwakami
N
N
Sugano
N
N
D000818:Animals; D002467:Cell Nucleus / Q000201:enzymology; D004247:DNA / Q000378:metabolism* / Q000528:radiation effects; D004260:DNA Repair / Q000502:physiology; D004269:DNA, Bacterial / Q000378:metabolism / Q000528:radiation effects; D004277:DNA, Single-Stranded / Q000378:metabolism / Q000528:radiation effects; D003851:Deoxyribonucleases / Q000302:isolation & purification / Q000378:metabolism*; D004926:Escherichia coli / Q000378:metabolism; D066298:In Vitro Techniques; D008099:Liver / Q000201:enzymology; D008274:Magnesium / Q000494:pharmacology; D051381:Rats; D014466:Ultraviolet Rays
D004269:DNA, Bacterial; D004277:DNA, Single-Stranded; D004247:DNA; D003851:Deoxyribonucleases; D008274:Magnesium