In enzymology, an uridine nucleosidase () is an enzyme that catalyzes the chemical reaction uridine + H2O D-ribose + uracil Thus, the two substrates of this enzyme are uridine and H2O, whereas its two products are D-ribose and uracil. This enzyme belongs to the family of hydrolases, specifically those glycosylases that hydrolyse N-glycosyl compounds. The systematic name of this enzyme class is uridine ribohydrolase. This enzyme is also called uridine hydrolase. This enzyme participates in pyrimidine metabolism. Structural studies As of late 2007, 23 structures have been solved for this class of enzymes, with PDB accession codes , , , , , , , , , , , , , , , , , , , , , , and . References EC 3.2.2 Enzymes of known structure