S1 nuclease-sensitive sites in yeast DNA: an assay for radiation-induced base damage.
DNA has been isolated from gamma-irradiated yeast cells and then treated with the enzyme S1 nuclease. This enzyme cleaves DNA specifically at sites where localized denaturation has occurred and can therefore be used as a lesion probe to identify regions in the DNA where base-pairing has been disrupted. By analysing the number of single strand breaks, double strand breaks and alkali-labile sites in the DNA before and after treatment with S1 nuclease, it has been possible to calculate the number of S1 nuclease-sensitive sites induced as a result of exposure to ionizing radiation. These sites were found to occur with a frequency about twice that of the double strand break and are thought to result from a primary ionization event in the DNA.
D003037:Cobalt Radioisotopes; D004271:DNA, Fungal / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D004720:Endonucleases; D005720:Gamma Rays; D012441:Saccharomyces cerevisiae / Q000528:radiation effects*; D015719:Single-Strand Specific DNA and RNA Endonucleases
D003037:Cobalt Radioisotopes; D004271:DNA, Fungal; D004720:Endonucleases; D015719:Single-Strand Specific DNA and RNA Endonucleases