Alpha amylase catalytic domain found in cyclomaltodextrinases and related proteins. Cyclomaltodextrinase (CDase; EC3.2.1.54), neopullulanase (NPase; EC 3.2.1.135), and maltogenic amylase (MA; EC 3.2.1.133) catalyze the hydrolysis of alpha-(1,4) glycosidic linkages on a number of substrates including cyclomaltodextrins (CDs), pullulan, and starch. These enzymes hydrolyze CDs and starch to maltose and pullulan to panose by cleavage of alpha-1,4 glycosidic bonds whereas alpha-amylases essentially lack activity on CDs and pullulan. They also catalyze transglycosylation of oligosaccharides to the C3-, C4- or C6-hydroxyl groups of various acceptor sugar molecules. Since these proteins are nearly indistinguishable from each other, they are referred to as cyclomaltodextrinases (CMDs). The Alpha-amylase family comprises the largest family of glycoside hydrolases (GH), with the majority of enzymes acting on starch, glycogen, and related oligo- and polysaccharides. These proteins catalyze the transformation of alpha-1,4 and alpha-1,6 glucosidic linkages with retention of the anomeric center. The protein is described as having 3 domains: A, B, C. A is a (beta/alpha) 8-barrel; B is a loop between the beta 3 strand and alpha 3 helix of A; C is the C-terminal extension characterized by a Greek key. The majority of the enzymes have an active site cleft found between domains A and B where a triad of catalytic residues (Asp, Glu and Asp) performs catalysis. Other members of this family have lost the catalytic activity as in the case of the human 4F2hc, or only have 2 residues that serve as the catalytic nucleophile and the acid/base, such as Thermus A4 beta-galactosidase with 2 Glu residues (GH42) and human alpha-galactosidase with 2 Asp residues (GH31). The family members are quite extensive and include: alpha amylase, maltosyltransferase, cyclodextrin glycotransferase, maltogenic amylase, neopullulanase, isoamylase, 1,4-alpha-D-glucan maltotetrahydrolase, 4-alpha-glucotransferase, oligo-1,6-glucosidase, amylosucrase, sucrose phosphorylase, and amylomaltase.

maltodextrin glucosidase; Provisional

Alpha amylase, catalytic domain. Alpha amylase is classified as family 13 of the glycosyl hydrolases. The structure is an 8 stranded alpha/beta barrel containing the active site, interrupted by a ~70 a.a. calcium-binding domain protruding between beta strand 3 and alpha helix 3, and a carboxyl-terminal Greek key beta-barrel domain.

Glycosidase [Carbohydrate transport and metabolism].

Alpha amylase catalytic domain found in bacterial Alpha-amylases (also called 1,4-alpha-D-glucan-4-glucanohydrolase). AmyA (EC 3.2.1.1) catalyzes the hydrolysis of alpha-(1,4) glycosidic linkages of glycogen, starch, related polysaccharides, and some oligosaccharides. This group includes Chloroflexi, Dictyoglomi, and Fusobacteria. The Alpha-amylase family comprises the largest family of glycoside hydrolases (GH), with the majority of enzymes acting on starch, glycogen, and related oligo- and polysaccharides. These proteins catalyze the transformation of alpha-1,4 and alpha-1,6 glucosidic linkages with retention of the anomeric center. The protein is described as having 3 domains: A, B, C. A is a (beta/alpha) 8-barrel; B is a loop between the beta 3 strand and alpha 3 helix of A; C is the C-terminal extension characterized by a Greek key. The majority of the enzymes have an active site cleft found between domains A and B where a triad of catalytic residues (Asp, Glu and Asp) performs catalysis. Other members of this family have lost the catalytic activity as in the case of the human 4F2hc, or only have 2 residues that serve as the catalytic nucleophile and the acid/base, such as Thermus A4 beta-galactosidase with 2 Glu residues (GH42) and human alpha-galactosidase with 2 Asp residues (GH31). The family members are quite extensive and include: alpha amylase, maltosyltransferase, cyclodextrin glycotransferase, maltogenic amylase, neopullulanase, isoamylase, 1,4-alpha-D-glucan maltotetrahydrolase, 4-alpha-glucotransferase, oligo-1,6-glucosidase, amylosucrase, sucrose phosphorylase, and amylomaltase.

Crystalstructure of Bacillus stearothermophilus neopullulanase [Geobacillus stearothermophilus],1J0H_B Crystal structure of Bacillus stearothermophilus neopullulanase [Geobacillus stearothermophilus],1J0I_A Crystal structure of neopullulanase complex with panose [Geobacillus stearothermophilus],1J0I_B Crystal structure of neopullulanase complex with panose [Geobacillus stearothermophilus]

Alpha-amylaseIi (tvaii) From Thermoactinomyces Vulgaris R-47 [Thermoactinomyces vulgaris],1BVZ_B Alpha-amylase Ii (tvaii) From Thermoactinomyces Vulgaris R-47 [Thermoactinomyces vulgaris],1JI2_A Improved X-ray Structure of Thermoactinomyces vulgaris R-47 alpha-Amylase 2 [Thermoactinomyces vulgaris],1JI2_B Improved X-ray Structure of Thermoactinomyces vulgaris R-47 alpha-Amylase 2 [Thermoactinomyces vulgaris],3A6O_A Crystal structure of Thermoactinomyces vulgaris R-47 alpha-amylase 2/acarbose complex [Thermoactinomyces vulgaris],3A6O_B Crystal structure of Thermoactinomyces vulgaris R-47 alpha-amylase 2/acarbose complex [Thermoactinomyces vulgaris]

ChainA, neopullulanase [Geobacillus stearothermophilus],1J0J_B Chain B, neopullulanase [Geobacillus stearothermophilus],1J0K_A Chain A, neopullulanase [Geobacillus stearothermophilus],1J0K_B Chain B, neopullulanase [Geobacillus stearothermophilus]

ChainA, Alpha-amylase II [Thermoactinomyces vulgaris],1WZM_B Chain B, Alpha-amylase II [Thermoactinomyces vulgaris]

ChainA, ALPHA AMYLASE II [Thermoactinomyces vulgaris],1JF6_B Chain B, ALPHA AMYLASE II [Thermoactinomyces vulgaris]

Neopullulanase OS=Geobacillus stearothermophilus OX=1422 GN=nplT PE=1 SV=1

Neopullulanase 2 OS=Thermoactinomyces vulgaris OX=2026 GN=tvaII PE=1 SV=1

Cyclomaltodextrinase OS=Geobacillus thermopakistaniensis (strain MAS1) OX=1408282 GN=T260_08735 PE=1 SV=1

Cyclomaltodextrinase OS=Bacillus sp. OX=1409 GN=CDI5 PE=1 SV=1

Maltogenic alpha-amylase OS=Bacillus acidopullulyticus OX=28030 PE=3 SV=1