NMN nucleosidase

In enzymology, a NMN nucleosidase (EC 3.2.2.14) is an enzyme that catalyzes the chemical reaction

nicotinamide D-ribonucleotide + H₂O ⇌ D-ribose 5-phosphate + nicotinamide

Thus, the two substrates of this enzyme are nicotinamide D-ribonucleotide and H₂O, whereas its two products are D-ribose 5-phosphate and nicotinamide.

This enzyme belongs to the family of hydrolases, specifically those glycosylases that hydrolyse N-glycosyl compounds. The systematic name of this enzyme class is nicotinamide-nucleotide phosphoribohydrolase. Other names in common use include NMNase, nicotinamide mononucleotide nucleosidase, nicotinamide mononucleotidase, NMN glycohydrolase, and NMNGhase. This enzyme participates in nicotinate and nicotinamide metabolism.