Canalicular ectonucleoside NTPDase responsible for the main hepatic NTPDase activity. Ectonucleoside ATPases catalyze the hydrolysis of gamma- and beta-phosphate residues of nucleotides, playing a central role in concentration of extracellular nucleotides. a ribonucleoside 5'-triphosphate + 2 H2O = a ribonucleoside 5'-phosphate + 2 H(+) + 2 phosphate Ca(2+) or Mg(2+). Has lower efficiency with Mg(2+). N-glycosylated. Belongs to the GDA1/CD39 NTPase family.