. "Catalysis of the reaction: H2O + a pyrimidine 5'-nucleotide = ribose-5-phosphate + a pyrimidine." . . "pyrimidine-5'-nucleotide nucleosidase activity" . "Pyr5N activity" . "pyrimidine nucleotide N-ribosidase activity" . "pyrimidine-5'-nucleotide phosphoribo(deoxyribo)hydrolase activity" . . .