There are many characterised protein families with Glycoside hydrolase activity EC 3.2.1.. These enzymes hydrolyse the glycosidic bond between two or more carbohydrates, or between a carbohydrate and a non-carbohydrate moiety. Families are defined based on their sequence similarity.[1][2][3] This classification is available on the CAZy (CArbohydrate-Active EnZymes) web site.[4] Because the fold of proteins is better conserved than their sequences, some of the families can be grouped into 'clans' (superfamilies). As of October 2011, CAZy includes 128 families of glycosyl hydrolases, grouped into 14 clans.