[Purification and properties of intracellular nuclease of a competent strain of Bacillus subtilis].
A new nuclease was isolated from a membrane-nucleoproteid complex (MNC) of the cell lysate of the competent strain Bacillus subtilis SB25 his2trp2 and purified 674-fold. It differs from the known exonucleases of Bacillus subtilis by the place of "attacking" the phosphodiester bond, by the absence of the specificity towards the end groups of denatured DNA and by a high pH optimum. Isolation and purification were performed as follows: cell destroying by lysozyme and osmotic shock, isolating the MNC by centrifugation, treating the MNC with pancreatic RNase and dialysis with Ca+2 ions against Tris-acetate buffer, chromatography on CM-and phosphocellulose. The nuclease of the partially purified preparation was activated by Ca+2 ions with the optimal concentration 0.5-1.0 mM. It hydrolysed denatured DNA and RNA with the pH optimum at 10.0-10.5. The main products of the denatured DNA hydrolysis were mono- and dinucleotides with 5'-end phosphate. The enzyme is insensitive to the end hydroxyl and phosphate groups of denatured DNA and was completely inhibited by 1.0 mM EDTA.
D001412:Bacillus subtilis / Q000201:enzymology*; D002462:Cell Membrane / Q000201:enzymology; D002845:Chromatography / Q000379:methods; D003851:Deoxyribonucleases / Q000032:analysis / Q000302:isolation & purification*; D005092:Exonucleases / Q000032:analysis / Q000302:isolation & purification; D009698:Nucleoproteins / Q000302:isolation & purification; D012260:Ribonucleases / Q000032:analysis / Q000302:isolation & purification*
D009698:Nucleoproteins; D003851:Deoxyribonucleases; D005092:Exonucleases; D012260:Ribonucleases
Ochistka i nekotorye svoĭstva vnutrikletochnoĭ nukleazy kompetentnogo shtamma Bacillus subtilis.