Catalyzes the hydrolysis of nucleoside triphosphates and diphosphates in a calcium- or magnesium-dependent manner. Preferentially hydrolyzes nucleoside 5'-triphosphates, with substrate preference for UTP > GTP > CTP. Hydrolyzes nucleoside diphosphates only to a minor extent (By similarity). In contrast to its human ortholog is able to hydrolyze ATP. In the epithelial cells of small intestine controls luminal ATP levels, therefore regulating Th17-cell development (PubMed:23241884). a ribonucleoside 5'-triphosphate + H2O = a ribonucleoside 5'-diphosphate + H(+) + phosphate H2O + UTP = H(+) + phosphate + UDP GTP + H2O = GDP + H(+) + phosphate CTP + H2O = CDP + H(+) + phosphate ATP + H2O = ADP + H(+) + phosphate Widely expressed. Expressed at high level in brain, kidney, liver, testis and small intestin. Weakly expressed in lung, thymus and heart. Deficient mice are born at the normal Mendelian ratios and grow healthily until 16 week of age. Normal lymphocyte development is observed. However deficient mice shown an increased in ATP concentrations in the small intestinal lumen and increased numbers of IL-17-producing Th17 cells in the small intestinal lamina propria. They show increased resistance to Citrobacter rodentium infection and increased susceptibility to experimental autoimmune encephalomyelitis. Belongs to the GDA1/CD39 NTPase family.