Glycoside hydrolase, family 45 (IPR000334)

Short name: Glyco_hydro_45

Overlapping homologous superfamilies

Domain 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 45 GH45 comprises enzymes with only one known activity; endoglucanase (EC:

The microbial degradation of cellulose and xylans requires several types of enzymes such as endoglucanases, cellobiohydrolases (EC: (exoglucanases), or xylanases (EC: [PMID: 2252383, PMID: 1886523]. Fungi and bacteria produce 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 K or as the glycosyl hydrolases family 45 [PMID: 8352747]. The best conserved regions in these enzymes is located in the N-terminal section. It contains an aspartic acid residue which has been shown [PMID: 8377830] to act as a nucleophile in the catalytic mechanism. This also has several cysteines that are involved in forming disulphide bridges.

GO terms

Biological Process

GO:0005975 carbohydrate metabolic process

Molecular Function

GO:0008810 cellulase activity

Cellular Component

No terms assigned in this category.

Contributing signatures

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