Effect of activators and inhibitors on the activity of mitochondrial DNA polymerase

At a concentration of 0.5 to 3 mmol/L, ATP stimulates the activity of mitochondrial DNA polymerase ofNeurospora crassa under the optimum reaction conditions; at higher concentrations, an inhibitory effect is observed. 4-Chloromercuribenzoate (1 mmol/L), a thiol inhibitor, decreases the enzyme activity two-fold, while N-ethylmaleimide (2 mmol/L) has no effect. Ethidium bromide (up to 10 μmol/L) and heparin (up to 0.4 μg/mL) reduce the activity by 60%. ddTTP does not affect the DNA polymerase reaction. The bestin vitro template is the activated calf-thymus DNA. 2nd report of the series Mitochondrial DNA polymerase from the poky mutant ofNeurospora crassa; 1st report:Biológia (Bratislava) 45, 601–606 (1990). Translated by Č. Novotny