title: Studies on deoxyribonucleases from Saccharomyces cerevisiae. Characterization of two endonuclease activities with a preference for double-stranded DNA.
abstract: Two new endonuclease activities, endonuclease B and endonuclease C, obtained from yeast nuclear preparations have been separated and partially characterized. Endonuclease B has a primary requirement for Mn2+ which cannot be replaced by Mg2+ or Ca2+, and makes single-strand scissions in double-stranded DNA. Endonculease C is activated by either Mn2+ or Mg2+, and makes single-strand scissions with Mg2+, while with Mn2+, scissions are made which result in double-strand breaks. Neither enzyme is active on denatured DNA, and both are inhibited by yeast RNA. Both enzymes exhibit pH optima at pH 5.0 and PH 7.2, and leave 5'-phosphoryl termini.
mesh_terms: D002467:Cell Nucleus / Q000201:enzymology; D002852:Chromatography, Ion Exchange; D004279:DNA, Viral; D003851:Deoxyribonucleases / Q000037:antagonists & inhibitors / Q000302:isolation & purification; D004720:Endonucleases / Q000037:antagonists & inhibitors / Q000302:isolation & purification; D004789:Enzyme Activation; D006863:Hydrogen-Ion Concentration; D008274:Magnesium; D012313:RNA / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000648:ultrastructure
chemical_list: D004279:DNA, Viral; D012313:RNA; D003851:Deoxyribonucleases; D004720:Endonucleases; D008274:Magnesium