In enzymology, a N-methyl nucleosidase () is an enzyme that catalyzes the chemical reaction 7-methylxanthosine + H2O 7-methylxanthine + D-ribose Thus, the two substrates of this enzyme are 7-methylxanthosine and H2O, whereas its two products are 7-methylxanthine and D-ribose. This enzyme belongs to the family of hydrolases, specifically those glycosylases that hydrolyse N-glycosyl compounds. The systematic name of this enzyme class is 7-methylxanthosine ribohydrolase. Other names in common use include 7-methylxanthosine nucleosidase, N-MeNase, N-methyl nucleoside hydrolase, and methylpurine nucleosidase. References EC 3.2.2 Enzymes of unknown structure