Properties of a DNA-dependent ATPase from rat mitochondria.
A DNA-dependent ATPase has been highly purified from rat liver mitochondria and characterized. The enzyme catalyzes the hydrolysis of ATP or dATP in the presence of single-stranded DNA cofactor and a divalent cation. The Km values for ATP and dATP are 0.15 mM and 0.35 mM, respectively. The enzyme activity is highly sensitive to N-ethylmaleimide. The sedimentation coefficient of the enzyme is 8.3 S in a glycerol gradient. From this and data on Sephadex G-200 gel filtration, the molecular weight of the native enzyme was calculated to be about 190,000. All the natural single-stranded DNAs tested were equally effective for the ATPase activity, but synthetic deoxyhomopolymer poly(dC) was found to be more effective than natural single-stranded DNAs. Synthetic and natural RNAs had no effect on the activity.
D000251:Adenosine Triphosphatases / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D002413:Cations, Divalent; D004247:DNA / Q000494:pharmacology*; D004277:DNA, Single-Stranded / Q000494:pharmacology*; D004720:Endonucleases / Q000378:metabolism; D005092:Exonucleases / Q000378:metabolism; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D015636:Magnesium Chloride; D008930:Mitochondria, Liver / Q000201:enzymology*; D011089:Polydeoxyribonucleotides / Q000494:pharmacology; D051381:Rats; D013329:Structure-Activity Relationship
D002413:Cations, Divalent; D004277:DNA, Single-Stranded; D011089:Polydeoxyribonucleotides; D015636:Magnesium Chloride; D004247:DNA; D004720:Endonucleases; D005092:Exonucleases; D000251:Adenosine Triphosphatases; D008274:Magnesium