Catalysis of the reaction: a ribonucleoside 5'-triphosphate + 2 H2O = a ribonucleoside 5'-phosphate + 2 phosphate. This reaction consists of two distinct successive phosphate-releasing steps, with NDPs as intermediates. Apyrases are active against both di- and triphosphate nucleotides (NDPs and NTPs) and hydrolyze NTPs to nucleotide monophosphates (NMPs).
apyrase activity