Acta Biologica 32. (1981)
1. szám - Bánfalvi G.–Csuzi O.–Ohlbaum A.–Antoni F.: Separation of ATP-dependent DNase to ATPase and DNase
Ada biol. Acad. Sei. hung., 32 (1), 45 — 54 (1981) SEPARATION OF ATP-DEPENDENT DNASE TO ATPASE AND DNASE G. Bánfalvi, S. Csuzi, Adél Ohlbaum and F. Antoni INSTITUTE OF BIOCHEMISTRY I, SEMMELWEIS UNIVERSITY MEDICAL SCHOOL, BUDAPEST, HUNGARY (Received 1979- 11—30) Abstract A 250-fold purified ATP-dependent DNase from Bacillus cereus has been separated to DNA-dependent ATP ase I and II and a DNase specific for single-stranded DNA (ssDNase) by means of high resolution of DEAE cellulose chromatography. Simultaneously with the separation of ATPases and ssDNase, a decrease in ATP-dependent DNase activity was observed. Complete separation resulted in the total loss of ATP- dependent DNase activity. Reconstitution of ATP-stimulated DNase activity was dependent on the ratio of the combined ATPase II and ssDNase. Introduction Exonuclease V of Escherichia coli, also called rec BC nuclease, is an ATP- dependent enzyme having both double-stranded and single-stranded exonucleolytic activities [16, 21, 24], as well as single-stranded endonucleolytic [16] and DNA-dependent ATPase activities among its multifunctional properties. ATP-dependent DNase activity has not yet been described in eukaryotic cells, however, it has been found in several bacterial strains [3, 8, 11, 12, 13, 15, 16, 20, 21, 24, 26, 28] and seems to be universal in prokaryotic cells. On the basis of the probable role of the E. coli enzyme, it is also regarded as a “recombination enzyme” [29]. ATP-dependent DNase is required for normal genetic recombination in other bacterial strains [12, 28], too. The properties of ATP-dependent DNase from Bacillus cereus have been described earlier [5]. The questions arising from partial purification and characterization of the B. cereus enzyme [6] were the following. 1. The specific activity of ATP-dependent DNase increased about 4200- fold, while the increase of the specific activity of DNA-dependent ATPase was only about 100-fold in the same purification procedure. 2. The properties of the ATPase were similar to the characteristics of DNA-dependent ATPases, without DNase activities isolated from E. coli [1] and from B. subtilis [31]. Acta Biologien Academiae Scienliaruni Hurigaricae 32, 1981