TY - JOUR TI - Removal of pyrimidine dimers from Saccharomyces cerevisiae nuclear DNA under nongrowth conditions as detected by a sensitive, enzymatic assay AB - A sensitive and quantitative procedure for the detection of pyrimidine dimers in yeast nuclear DNA is described. The assay employs dimer-specific, endonuclease activities from Micrococcus luteus together with DNA sedimentation through calibrated, alkaline sucrose gradients to detect endonuclease-induced, single-strand breaks. Breaks were induced in a dose-dependent manner from 0 to 80 J m/sup -2/ at 254 nm and in numbers equivalent to the numbers of dimers induced by similar doses. Endonuclease-sensitive sites in the wild-type, haploid strain S288C, after irradiation with 5 J m/sup -2/ (254 nm), were removed in less than 5 min when cells were incuba ted in buffer (pH 7.0) at 28/sup 0/C. After irra diation with dos es from 30 to 100 J m/sup -2/ site removal in S288C required longer postirradiation incubations and was about 90% complete. In a radiation-sensitive strain carrying the mutant allele rad 4-3 the number of endonuclease-sensitive sites remained constant for 6 h after irradiation with 5 J m/sup -2/. The retention of sites in this strain indicates that it is defective in the excision of pyrimidine dimers. (Auth. AU - "Reynolds, R J [Tennessee Univ., Oak Ridge (USA). Graduate School of Biomedical Sciences]" KW - "63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT." KW - "DNA" KW - "BIOLOGICAL REPAIR" KW - "PYRIMIDINES" KW - "BIOASSAY" KW - "BIOLOGICAL LOCALIZATION" KW - "DIMERS" KW - "DOSE-RESPONSE RELATIONSHIPS" KW - "FAR ULTRAVIOLET RADIATION" KW - "LOW DOSE IRRADIATION" KW - "NUCLEASES" KW - "SACCHAROMYCES CEREVISIAE" KW - "SEDIMENTATION" KW - "AZINES" KW - "BIOLOGICAL RECOVERY" KW - "BIOMASS" KW - "ELECTROMAGNETIC RADIATION" KW - "ENERGY SOURCES" KW - "ENZYMES" KW - "FUNGI" KW - "HETEROCYCLIC COMPOUNDS" KW - "IRRADIATION" KW - "MICROORGANISMS" KW - "NUCLEIC ACIDS" KW - "ORGANIC COMPOUNDS" KW - "ORGANIC NITROGEN COMPOUNDS" KW - "PHOSPHOTRANSFERASES" KW - "PLANTS" KW - "RADIATIONS" KW - "RECOVERY" KW - "RENEWABLE ENERGY SOURCES" KW - "REPAIR" KW - "SACCHAROMYCES" KW - "TRANSFERASES" KW - "ULTRAVIOLET RADIATION" KW - "YEASTS" KW - "560112* - Radiation Effects on Biochemicals- In Microorganisms- (-1987)" DO - https://doi.org/ UR - PB - CY - Netherlands PY - 1978 DA - 1978-04-01 LA - English J2 - [] VL - 50:1 C1 - C2 - C3 - C4 - C5 - L3 - Journal Name: Mutat. Res.; (Netherlands); Journal Volume: 50:1 ER -