Glycoside hydrolase family 5

In molecular biology, glycoside hydrolase family 5 is a family of glycoside hydrolases , which 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 web site, and also discussed at CAZypedia, an online encyclopedia of carbohydrate active enzymes.

Glycoside hydrolase family 5 CAZY GH_5 comprises enzymes with several known activities including endoglucanase (); beta-mannanase (); exo-1,3-glucanase (); endo-1,6-glucanase (); xylanase (); endoglycoceramidase (); xanthanase.

The microbial degradation of cellulose and xylans requires several types of enzymes. Fungi and bacteria produces a spectrum of cellulolytic enzymes (cellulases) and xylanases which, on the basis of sequence similarities, can be classified into families. One of these families is known as the cellulase family A or as the glycosyl hydrolases family 5. One of the conserved regions in this family contains a conserved glutamic acid residue which is potentially involved in the catalytic mechanism.

In a recent study using Molecular Dynamics simulations, a considerable correlation between thermal stability and structural rigidity of members of family 5 with solved structures has been proved.