Glycoside hydrolasesEC3.2.1. 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 glycoside hydrolases, based on sequence similarity, has led to the definition of >100 different families.[1][2][3] This classification is available on the
CAZy web site,[4][5] and also discussed at CAZypedia, an online encyclopedia of carbohydrate active enzymes.[6][7]
Glycoside hydrolase family 45
CAZY GH_45 comprises enzymes with only one known activity;
endoglucanase (
EC3.2.1.4). This family is also known as cellulase family K.[8] The best conserved region in these enzymes is located in the N-terminal section. It contains an
aspartic acid residue which has been shown[9] to act as a
nucleophile in the catalytic mechanism. This also has several
cysteines that are involved in forming
disulphide bridges.