title: Purification and properties of a manganese-stimulated endonuclease from Bacillus subtilis.
abstract: An endonuclease stimulated by manganese or calcium ions was isolated from Bacillus subtilis. This enzyme attacked double- or single-stranded deoxyribonucleic acid from a variety of sources, including B. subtilis, and was purified from the material released into the medium during protoplast formation. The enzyme appeared as a single peak after glycerol gradient centrifugation and comprised approximately 30 to 35% of the protein in the most purified preparations, as estimated by gel electrophoresis. It had a molecular weight of about 46,000. The mode of action of the enzyme was endonucleolytic, and circular deoxyribonucleic acid was readily cleaved. The enzyme introduced a limited number of both double- and single-strand breaks into native deoxyribonucleic acid, generally yielding products of 1 X 10(6) daltons or more in size. The reasons for this limitation of cleavage were not clear. The activity of the enzyme was inhibited by low levels of Cu2+, Co2+, Hg2+, and Zn2+. It was also inhibited by high concentrations of NaCl. A role for this enzyme in bacterial transormation is suggested.
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology*; D002118:Calcium / Q000494:pharmacology; D002474:Cell-Free System; D004269:DNA, Bacterial / Q000378:metabolism; D004270:DNA, Circular / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000378:metabolism; D004279:DNA, Viral / Q000378:metabolism; D003851:Deoxyribonucleases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism; D004720:Endonucleases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism; D008345:Manganese / Q000494:pharmacology; D008970:Molecular Weight
chemical_list: D004269:DNA, Bacterial; D004270:DNA, Circular; D004277:DNA, Single-Stranded; D004279:DNA, Viral; D008345:Manganese; D003851:Deoxyribonucleases; D004720:Endonucleases; D002118:Calcium