Glycoside hydrolase, family 19 (IPR016283)

Short name: Glyco_hydro_19

Overlapping homologous superfamilies

Family relationships



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 [PMID: 7624375, PMID: 8535779]. This classification is available on the CAZy (CArbohydrate-Active EnZymes) web site.

Glycoside hydrolase family 19 GH19 comprises enzymes with only one known activity; chitinase (EC:

Chitinases [PMID: 1516675] are enzymes that catalyze the hydrolysis of the beta-1,4-N-acetyl-D-glucosamine linkages in chitin polymers. Chitinases belong to glycoside hydrolase families 18 or 19 [PMID: 1747104]. Chitinases of family 19 (also known as classes IA or I and IB or II) are enzymes from plants that function in the defence against fungal and insect pathogens by destroying their chitin-containing cell wall. Class IA/I and IB/II enzymes differ in the presence (IA/I) or absence (IB/II) of a N-terminal chitin-binding domain. The catalytic domain of these enzymes consist of about 220 to 230 amino acid residues.

GO terms

Biological Process

GO:0005975 carbohydrate metabolic process

Molecular Function

GO:0004568 chitinase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.