Glycoside hydrolases (O-Glycosyl hydrolases) are a widespread group of enzymes that hydrolyse the glycosidic bond between two or more carbohydrates, or between a carbohydrate and a non-carbohydrate moiety. A classification system for glycosyl hydrolases, based on sequence similarity, has led to the definition of numerous different families. This classification is available on the CAZy (CArbohydrate-Active EnZymes) web site. Because the fold of proteins is better conserved than their sequences, some of the families can be grouped in 'clans'. As of October 2011, CAZy includes 128 families of glycosyl hydrolases and 14 clans. Glycoside hydrolase family 1 Glycoside hydrolase family 2 Glycoside hydrolase family 3 Glycoside hydrolase family 4 Glycoside hydrolase family 5 Glycoside hydrolase family 6 Glycoside hydrolase family 7 Glycoside hydrolase family 8 Glycoside hydrolase family 9 Glycoside hydrolase family 10 Glycoside hydrolase family 11 Glycoside hydrolase family 12 Glycoside hydrolase family 13 Glycoside hydrolase family 14 Glycoside hydrolase family 15 Glycoside hydrolase family 16 Glycoside hydrolase family 17 Glycoside hydrolase family 18 Glycoside hydrolase family 19 Glycoside hydrolase family 20 Glycoside hydrolase family 21 Glycoside hydrolase family 22 Glycoside hydrolase family 23 Glycoside hydrolase family 24 Glycoside hydrolase family 25 Glycoside hydrolase family 26 Glycoside hydrolase family 27 Glycoside hydrolase family 28 Glycoside hydrolase family 29 Glycoside hydrolase family 30 Glycoside hydrolase family 31 Glycoside hydrolase family 32 Glycoside hydrolase family 33 Glycoside hydrolase family 34 Glycoside hydrolase family 35 Glycoside hydrolase family 36 Glycoside hydrolase family 37 Glycoside hydrolase family 38 Glycoside hydrolase family 39 Glycoside hydrolase family 40 Glycoside hydrolase family 41 Glycoside hydrolase family 42 Glycoside hydrolase family 43 Glycoside hydrolase family 44 Glycoside hydrolase family 45 Glycoside hydrolase family 46 Glycoside hydrolase family 47 Glycoside hydrolase family 48 Glycoside hydrolase family 49 Glycoside hydrolase family 50 Glycoside hydrolase family 51 Glycoside hydrolase family 52 Glycoside hydrolase family 53 Glycoside hydrolase family 54 Glycoside hydrolase family 55 Glycoside hydrolase family 56 Glycoside hydrolase family 57 Glycoside hydrolase family 58 Glycoside hydrolase family 59 Glycoside hydrolase family 60 Glycoside hydrolase family 61 Glycoside hydrolase family 62 Glycoside hydrolase family 63 Glycoside hydrolase family 64 Glycoside hydrolase family 65 Glycoside hydrolase family 66 Glycoside hydrolase family 67 Glycoside hydrolase family 68 Glycoside hydrolase family 69 Glycoside hydrolase family 70 Glycoside hydrolase family 71 Glycoside hydrolase family 72 Glycoside hydrolase family 73 Glycoside hydrolase family 74 Glycoside hydrolase family 75 Glycoside hydrolase family 76 Glycoside hydrolase family 77