InterPro: IPR003476 Glycoside hydrolase, family 42

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 group of beta-galactosidase enzymes (EC:3.2.1.23) belong to the glycosyl hydrolase 42 family GH42. The enzyme catalyses the hydrolysis of terminal, non-reducing terminal beta-D-galactosidase residues.