Glycoside hydrolase family 45
Encyclopedia
In molecular biology, glycoside hydrolase family 45 is a family
of glycoside hydrolases
.
Glycoside hydrolases 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. This classification is available on the CAZy(http://www.cazy.org/GH1.html) web site, and also discussed at CAZypedia, an online encyclopedia of carbohydrate active enzymes.
Glycoside hydrolase family 45 CAZY GH_45 comprises enzymes with only one known activity; endoglucanase . This family is also known as known as cellulase family K. The best conserved region in these enzymes is located in the N-terminal section. It contains an aspartic acid
residue which has been shown to act as a nucleophile
in the catalytic mechanism. This also has several cysteines
that are involved in forming disulphide bridges.
Protein family
A protein family is a group of evolutionarily-related proteins, and is often nearly synonymous with gene family. The term protein family should not be confused with family as it is used in taxonomy....
of glycoside hydrolases
Glycoside hydrolase
Glycoside hydrolases catalyze the hydrolysis of the glycosidic linkage to release smaller sugars...
.
Glycoside hydrolases are a widespread group of enzymes that hydrolyse the glycosidic bond
Glycosidic bond
In chemistry, a glycosidic bond is a type of covalent bond that joins a carbohydrate molecule to another group, which may or may not be another carbohydrate....
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(http://www.cazy.org/GH1.html) web site, and also discussed at CAZypedia, an online encyclopedia of carbohydrate active enzymes.
Glycoside hydrolase family 45 CAZY GH_45 comprises enzymes with only one known activity; endoglucanase . This family is also known as known as cellulase family K. The best conserved region in these enzymes is located in the N-terminal section. It contains an aspartic acid
Aspartic acid
Aspartic acid is an α-amino acid with the chemical formula HOOCCHCH2COOH. The carboxylate anion, salt, or ester of aspartic acid is known as aspartate. The L-isomer of aspartate is one of the 20 proteinogenic amino acids, i.e., the building blocks of proteins...
residue which has been shown to act as a nucleophile
Nucleophile
A nucleophile is a species that donates an electron-pair to an electrophile to form a chemical bond in a reaction. All molecules or ions with a free pair of electrons can act as nucleophiles. Because nucleophiles donate electrons, they are by definition Lewis bases.Nucleophilic describes the...
in the catalytic mechanism. This also has several cysteines
Cysteine
Cysteine is an α-amino acid with the chemical formula HO2CCHCH2SH. It is a non-essential amino acid, which means that it is biosynthesized in humans. Its codons are UGU and UGC. The side chain on cysteine is thiol, which is polar and thus cysteine is usually classified as a hydrophilic amino acid...
that are involved in forming disulphide bridges.