Glycoside hydrolase family 42

In molecular biology, glycoside hydrolase family 42 is a family of glycoside hydrolases.

Glycoside 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 glycoside hydrolases, based on sequence similarity, has led to the definition of >100 different families. This classification is available on the CAZy(http://www.cazy.org/GH1.html) web site, and also discussed at CAZypedia, an online encyclopedia of carbohydrate active enzymes.

The glycosyl hydrolase 42 family CAZY GH_42 comprises beta-galactosidase enzymes (EC 3.2.1.23). These enzyme catalyse the hydrolysis of terminal, non-reducing terminal beta-D-galactoside residues. The middle domain of these three-domain enzymes is involved in trimerisation.