Involved in the hydrolysis of the beta-gamma-phosphoanhydride linkage of triphosphate-containing substrates (inorganic or nucleoside-linked). Catalyzes the hydrolysis of inorganic triphosphate (PPPi), however it does not display significant activity towards long-chain polyphosphates. The existence of PPPi in living cells is still unclear, and PPPase activity might be the ancestral function of CYTH domain. It also has gamma-phosphatase activity on NTP substrates, but no adenylate cyclase or RNA triphosphatase activity. H2O + triphosphate = diphosphate + phosphate ATP + H2O = ADP + H(+) + phosphate PPPase is active in the presence of Mg(2+) ions, while no activity is observed in the presence of manganese ions. ATPase occurs in the presence of Mg(2+) ions as well as Mn(2+) and Co(2+) ions. Inhibited by 2.5 mM Ca(2+). Optimum pH is 9.5 (in the presence of Mg(2+)). No activity at pH 7.5. Optimum temperature is 45.50 degrees Celsius. Expressed only in the proximal meristematic zone of the root. Delayed root growth and reduced length and number of lateral roots.