Properties of ATP dependent deoxyribonuclease and its possible role in deoxyribonucleic acid degradation of bacillus cereus irradiated by ultraviolet light

DNA degradation and an increased level of DNAses in the crude extract of irradiated B. cereus culture has been observed. As a result of a more detailed study of ATP dependent DNAse, the optimum pH and ATP dependency, furthermore optimum ATP concentration were established. The enzyme degrades the native DNA at a rate about 4-5 times higher than the thermally denaturated DNA. Samples of the DNA irradiated by increasing doses of U.V.-light were hydrolysed at decreasing rates. The native and U.V. irradiated DNA were degraded at nearly equal rates, on this basis it is supposed that the enzyme preferentially forms a complex with the native rather than with the irradiated DNA