In enzymology, a cyclomaltodextrinase (EC 3.2.1.54) is an enzyme that catalyzes the chemical reaction In enzymology, a cyclomaltodextrinase (EC 3.2.1.54) is an enzyme that catalyzes the chemical reaction Thus, the two substrates of this enzyme are cyclomaltodextrin and H2O, whereas its product is linear maltodextrin. This enzyme belongs to the family of hydrolases, specifically those glycosidases that hydrolyse O- and S-glycosyl compounds. The systematic name of this enzyme class is cyclomaltodextrin dextrin-hydrolase (decyclizing). Other names in common use include cycloheptaglucanase, cyclohexaglucanase, and cyclodextrinase. This enzyme participates in starch and sucrose metabolism. As of late 2007, two structures have been solved for this class of enzymes, with PDB accession codes 1EA9 and 1H3G.