InterPro: IPR003469 Glycoside hydrolase, family 68

O-Glycosyl hydrolases EC:3.2.1. 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 85 different families [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 in clans.

This family consists of the glycosyl hydrolase 68 family (GH68), including several bacterial levansucrase enzymes, and invertase from Zymomonas. Levansucrase (EC:2.4.1.10), also known as beta-D-fructofuranosyl transferase, catalyses the conversion of sucrose and (2,6-beta-D-fructosyl)(N) to glucose and (2,6-beta-D-fructosyl)(N+1), where other sugars can also act as fructosyl acceptors. Invertase, or extracellular sucrase (EC:3.2.1.26), catalyses the hydrolysis of terminal non-reducing beta-D-fructofuranoside residues in beta-D-fructofuranosides.