In enzymology, a S-methyl-5'-thioadenosine phosphorylase is an enzyme that catalyzes the chemical reaction S-methyl-5'-thioadenosine + phosphate ⇌ {\displaystyle \rightleftharpoons } adenine + S-methyl-5-thio-alpha-D-ribose 1-phosphateThus, the two substrates of this enzyme are S-methyl-5'-thioadenosine and phosphate, whereas its two products are adenine and S-methyl-5-thio-alpha-D-ribose 1-phosphate. Wikipedia