In enzymology, a methylthioadenosine nucleosidase is an enzyme that catalyzes the chemical reaction S-methyl-5'-thioadenosine + H2O ⇌ {\displaystyle \rightleftharpoons } S-methyl-5-thio-D-ribose + adenineThus, the two substrates of this enzyme are S-methyl-5'-thioadenosine and H2O, whereas its two products are S-methyl-5-thio-D-ribose and adenine. Wikipedia