In molecular biology, glycoside hydrolase family 9 is a

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

glycoside hydrolase Glycoside hydrolases (also called glycosidases or glycosyl hydrolases) catalyze the hydrolysis of glycosidic bonds in complex sugars. They are extremely common enzymes with roles in nature including degradation of biomass such as cellulose (cel ...

Glycoside hydrolases Glycoside hydrolases (also called glycosidases or glycosyl hydrolases) catalyze the hydrolysis of glycosidic bonds in complex sugars. They are extremely common enzymes with roles in nature including degradation of biomass such as cellulose (cel ...

are a widespread group of enzymes that

hydrolyse Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis ...

the

glycosidic bond A glycosidic bond or glycosidic linkage is a type of covalent bond that joins a carbohydrate (sugar) molecule to another group, which may or may not be another carbohydrate. A glycosidic bond is formed between the hemiacetal or hemiketal group ...

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 CAZy is a database of Carbohydrate-Active enZYmes (CAZymes). The database contains a classification and associated information about enzymes involved in the synthesis, metabolism, and recognition of complex carbohydrates, i.e. disaccharides, olig ...

web site, and also discussed at CAZypedia, an online encyclopedia of carbohydrate active enzymes. Glycoside hydrolase family
CAZY GH_9
comprises enzymes with several known activities including

endoglucanase Cellulase (EC 3.2.1.4; systematic name 4-β-D-glucan 4-glucanohydrolase) is any of several enzymes produced chiefly by fungi, bacteria, and protozoans that catalyze cellulolysis, the decomposition of cellulose and of some related polysaccharide ...

() and cellobiohydrolase (). These enzymes were formerly known as cellulase family E. Cellulases (Endoglucanases) catalyse the endohydrolysis of 1,4-beta-D-glucosidic linkages in cellulose. GH9 family members have also been found in green microalgae (Chlamydomonas, Gonium and Volvox) that show highest sequence identity to endogenous GH9 cellulases from invertebrate metazoans

References

{{Portal bar, Biology, border=no EC 3.2.1 GH family Protein families