Glycoside hydrolase, family 46 (IPR000400)

Short name: Glyco_hydro_46

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 46 GH46 comprises enzymes with only one known activity; chitosanase (EC:

Chitosanase enzymes catalyse the endohydrolysis of beta-1,4-linkages between N-acetyl-D-glucosamine and D-glucosamine residues in a partly acetylated chitosan. Chitosan is a biopolymer of beta (1,4)-linked -D-glucosamine (GlcN) residues produced by partial or full deacetylation of chitin. Chitosanases play a role in defense against pathogens such as fungi and are found in microorganisms, fungi, viruses, and plants. Microbial chitosanases who members are the most prevalent can be divided into 3 subclasses based on the specificity of the cleavage positions for partial acetylated chitosan. Subclass I chitosanases such as N174 can split GlcN-GlcN and GlcNAc-GlcN linkages, whereas subclass II chitosanases such as Bacillus sp. no. 7-M can cleave only GlcN-GlcN linkages. Subclass III chitosanases such as MH-K1 chitosanase are the most versatile and can split both GlcN-GlcN and GlcN-GlcNAc linkages [PMID: 9723170,PMID: 8564542,PMID: 8564539,PMID: 12369923].

GO terms

Biological Process

GO:0005975 carbohydrate metabolic process

Molecular Function

GO:0016977 chitosanase activity

Cellular Component

GO:0005576 extracellular region

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
  • cd00978 (chitosanase_glyco_hydro_46)
PROSITE patterns