Purification and properties of a manganese-stimulated deoxyribonuclease produced during sporulation of Bacillus subtilis.
A DNAase (deoxyribonuclease) was isolated from culture supernatants of sporulating Bacillus subtilis 168. The purified enzyme migrated as a single band during polyacrylamide-gel electrophoresis. The enzyme differs from other DNAases of B. subtilis in molecular weight, metal-ion requirement and mode of action. The enzyme was inactive in the absence of metal ions, and exhibited optimum activity with 10 mM-Mn2+, although Mg2+, Cd2+ and Co2+ could also permit some activity. The pH optimum for the enzyme was pH 7.5, and it degraded linear-duplex DNA or closed-circular-duplex DNA to acid-soluble material. There was little or no activity on single-stranded DNA or rRNA. Sucrose-gradient analysis of the products of DNAase action on bacteriophage T7 DNA showed that endonucleolytic cleavage had occurred by the introduction of single-strand breaks in both strands of the duplex. The molecular weight of the enzyme was determined, by gel filtration on Sephadex G-75, to be 12000.
D001412:Bacillus subtilis / Q000201:enzymology* / Q000502:physiology; D002413:Cations, Divalent / Q000494:pharmacology; D002499:Centrifugation, Density Gradient; D004279:DNA, Viral / Q000378:metabolism; D003851:Deoxyribonucleases / Q000302:isolation & purification / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel; D006863:Hydrogen-Ion Concentration; D008345:Manganese / Q000494:pharmacology*; D008970:Molecular Weight; D013171:Spores, Bacterial; D013379:Substrate Specificity
D002413:Cations, Divalent; D004279:DNA, Viral; D008345:Manganese; D003851:Deoxyribonucleases