Glucoamylase (glucan-1,4-alpha-glucosidase), GH15 family [Carbohydrate transport and metabolism].

oligosaccharide amylase. The name of this type of amylase is based on the characterization of an glucoamylase family enzyme from Thermoactinomyces vulgaris. The T. vulgaris enzyme was expressed in E. coli and, like other glucoamylases, it releases beta-D-glucose from starch. However, unlike previously characterized glucoamylases, this T. vulgaris amylase hydrolyzes maltooligosaccharides (maltotetraose, maltose) more efficiently than starch (1), indicating this enzyme belongs to a class of glucoamylase-type enzymes with oligosaccharide-metabolizing activity.

Glycosyl hydrolases family 15. In higher organisms this family is represented by phosphorylase kinase subunits.

Glucodextranase, domain N. Members of this family, which are uniquely found in bacterial and archaeal glucoamylases and glucodextranases, adopt a structure consisting of 17 antiparallel beta-strands. These beta-strands are divided into two beta-sheets, and one of the beta-sheets is wrapped by an extended polypeptide, which appears to stabilize the domain. Members of this family are mainly concerned with catalytic activity, hydrolysing alpha-1,6-glucosidic linkages of dextran to release beta-D-glucose from the non-reducing end via an inverting reaction mechanism.

Glycoside hydrolase family 15, N-terminal domain. Members of this family are N-terminal domains uniquely found in bacterial and archaeal glucoamylases and glucodextranases. Glucoamylase (glucan 1,4-alpha-glucosidase; 4-alpha-D-glucan glucohydrolase; amyloglucosidase; exo-1,4-alpha-glucosidase; gamma-amylase; lysosomal alpha-glucosidase; EC 3.2.1.3) hydrolyzes beta-1,4-glucosidic linkages of starch, glycogen and malto-oligosaccharides, releasing beta-D-glucose from the non-reducing end. Glucodextranase (glucan 1,6-alpha-glucosidase; exo-1,6-alpha-glucosidase; EC 3.2.1.70) uses an inverting reaction mechanism to hydrolyze alpha-1,6-glucosidic linkages of dextran and related oligosaccharides, releasing beta-D-glucose from the non-reducing end. These N-terminal domains adopt a structure consisting of antiparallel beta-strands, divided into two beta-sheets, with one sheet wrapped by an extended polypeptide, which appears to stabilize the domain. The function of these domains in the enzymes is as yet unknown. However, it is suggested that domain N of bacterial GA is involved in folding and/or the thermostability of the A domain that forms an (alpha/alpha)6-barrel structure.

Uncharacterized glycosyl hydrolase MJ1610 OS=Methanocaldococcus jannaschii (strain ATCC 43067 / DSM 2661 / JAL-1 / JCM 10045 / NBRC 100440) OX=243232 GN=MJ1610 PE=3 SV=1