Excision repair of gamma-ray-induced alkali-stable DNA lesions with the help of gamma-endonuclease from Micrococcus luteus.
gamma-Endonuclease Y, an enzyme that hydrolyses phosphodiester bonds at alkalistable lesions in gamma-irradiated (N2, tris buffer) DNA, has been partially purified from Micrococcus luteus. The enzyme has a molecular weight of about 19 000, induces single-strand breaks with 3'OH-5'PO4 termini and contains endonuclease activity towards DNA treated with 7-bromomethylbenz(a)anthracene. gamma-Endonuclease Y induces breaks in OsO4-treated poly(dA-dT) and apparently is specific towards gamma-ray-induced base lesions of the t' type. The complete excision repair of gamma-endonuclease Y substrate sites has been performed in vitro by gamma-endonuclease Y, DNA polymerase and ligase.
D003090:Coliphages / Q000201:enzymology; D004247:DNA / Q000528:radiation effects; D004260:DNA Repair; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D004720:Endonucleases / Q000302:isolation & purification / Q000378:metabolism*; D005720:Gamma Rays; D008837:Micrococcus / Q000201:enzymology*; D011067:Poly dA-dT / Q000378:metabolism / Q000528:radiation effects; D011118:Polynucleotide Ligases / Q000378:metabolism
D011067:Poly dA-dT; D004247:DNA; D004259:DNA-Directed DNA Polymerase; D004720:Endonucleases; D011118:Polynucleotide Ligases