Glycoside hydrolase family 15
Encyclopedia
In molecular biology, glycoside hydrolase family 15 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 15 CAZY GH_15 comprises enzymes with several known activities; glucoamylase ; alpha-glucosidase
; glucodextranase .
Glucoamylase (GA) catalyses the release of D-glucose from the non-reducing ends of starch and other oligo- or poly-saccharides. Studies of fungal GA have indicated 3 closely clustered acidic residues that play a role in the catalytic mechanism. This region is also conserved in a recently sequenced bacterial GA.
The 3D structure of the pseudo-tetrasaccharide
acarbose
complexed with glucoamylase II(471) from Aspergillus awamori var. X100 has been determined to 2.4A
resolution. The protein belongs to the mainly alpha class, and contains 19 helices and 9 strands.
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 15 CAZY GH_15 comprises enzymes with several known activities; glucoamylase ; alpha-glucosidase
Alpha-glucosidase
Alpha-glucosidase is a glucosidase acting upon 1,4-alpha bonds. This is in contrast to beta-glucosidase.The term maltase, which refers to an enzyme cleaving maltose, is nearly equivalent.Types include:* Acid alpha-glucosidase* neutral** GANAB** GANC...
; glucodextranase .
Glucoamylase (GA) catalyses the release of D-glucose from the non-reducing ends of starch and other oligo- or poly-saccharides. Studies of fungal GA have indicated 3 closely clustered acidic residues that play a role in the catalytic mechanism. This region is also conserved in a recently sequenced bacterial GA.
The 3D structure of the pseudo-tetrasaccharide
Tetrasaccharide
A tetrasaccharide is a carbohydrate which gives upon hydrolysis four molecules of the same or different monosaccharides. For example, stachyose upon hydrolysis gives one molecule each of glucose and fructose and two molecules of galactose. The general formula of a tetrasaccharide is typically...
acarbose
Acarbose
Acarbose is an anti-diabetic drug used to treat type 2 diabetes mellitus and, in some countries, prediabetes. It is a generic sold in Europe and China as Glucobay , in North America as Precose , and in Canada as Prandase...
complexed with glucoamylase II(471) from Aspergillus awamori var. X100 has been determined to 2.4A
Ångström
The angstrom or ångström, is a unit of length equal to 1/10,000,000,000 of a meter . Its symbol is the Swedish letter Å....
resolution. The protein belongs to the mainly alpha class, and contains 19 helices and 9 strands.