Enzymatic degradation of uracil-containing DNA. II. Evidence for N-glycosidase and nuclease activities in unfractionated extracts of Bacillus subtilis.
Further studies have confirmed our earlier observations that in the presence of EDTA, degradation of phage PBS2 [3H]uracil-labeled DNA is effected by an N-glycosidase activity in extracts of Bacillus subtilis that removes free uracil from DNA. In addition, such extracts contain a nuclease activity that attacks PBS2 DNA in the presence of CaCl2. The nuclease activity is not observed under conditions that inactivate N-glycosidase activity but does attack DNA that has been preincubated to remove uracil by N-glycosidase action. We therefore postulate that the nuclease requires N-glycosidase action to generate substrate for its activity, i.e., the nuclease appears to attack depyrimidinated sites rather than uracil sites in phage PBS2 DNA.
D001412:Bacillus subtilis / Q000201:enzymology; D001435:Bacteriophages / Q000254:growth & development / Q000378:metabolism*; D002122:Calcium Chloride / Q000494:pharmacology; D002474:Cell-Free System; D004279:DNA, Viral / Q000378:metabolism*; D003851:Deoxyribonucleases / Q000378:metabolism*; D004492:Edetic Acid / Q000494:pharmacology; D006026:Glycoside Hydrolases / Q000378:metabolism*; D014498:Uracil / Q000378:metabolism
D004279:DNA, Viral; D014498:Uracil; D004492:Edetic Acid; D003851:Deoxyribonucleases; D006026:Glycoside Hydrolases; D002122:Calcium Chloride