Alpha amylase catalytic domain found in archaeal and 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 firmicutes, bacteroidetes, and proteobacteria. 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.

Alpha amylase catalytic domain family. 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; and 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 this 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.

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].

glycosyl hydrolase family 36 (GH36). GH36 enzymes occur in prokaryotes, eukaryotes, and archaea with a wide range of hydrolytic activities, including alpha-galactosidase, alpha-N-acetylgalactosaminidase, stachyose synthase, and raffinose synthase. All GH36 enzymes cleave a terminal carbohydrate moiety from a substrate that varies considerably in size, depending on the enzyme, and may be either a starch or a glycoprotein. GH36 members are retaining enzymes that cleave their substrates via an acid/base-catalyzed, double-displacement mechanism involving a covalent glycosyl-enzyme intermediate. Two aspartic acid residues have been identified as the catalytic nucleophile and the acid/base, respectively.

ChainA, Pullulanase type II, GH13 family [Thermococcus kodakarensis]

CrystalStructure of E.Coli Branching Enzyme in complex with maltoheptaose [Escherichia coli],4LPC_B Crystal Structure of E.Coli Branching Enzyme in complex with maltoheptaose [Escherichia coli],4LPC_C Crystal Structure of E.Coli Branching Enzyme in complex with maltoheptaose [Escherichia coli],4LPC_D Crystal Structure of E.Coli Branching Enzyme in complex with maltoheptaose [Escherichia coli],4LQ1_A Crystal Structure of E.Coli Branching Enzyme in complex with maltohexaose [Escherichia coli],4LQ1_B Crystal Structure of E.Coli Branching Enzyme in complex with maltohexaose [Escherichia coli],4LQ1_C Crystal Structure of E.Coli Branching Enzyme in complex with maltohexaose [Escherichia coli],4LQ1_D Crystal Structure of E.Coli Branching Enzyme in complex with maltohexaose [Escherichia coli],5E6Y_A Crystal structure of E.Coli branching enzyme in complex with alpha cyclodextrin [Escherichia coli O139:H28 str. E24377A],5E6Y_B Crystal structure of E.Coli branching enzyme in complex with alpha cyclodextrin [Escherichia coli O139:H28 str. E24377A],5E6Y_C Crystal structure of E.Coli branching enzyme in complex with alpha cyclodextrin [Escherichia coli O139:H28 str. E24377A],5E6Y_D Crystal structure of E.Coli branching enzyme in complex with alpha cyclodextrin [Escherichia coli O139:H28 str. E24377A],5E6Z_A Crystal structure of Ecoli Branching Enzyme with beta cyclodextrin [Escherichia coli O139:H28 str. E24377A],5E6Z_B Crystal structure of Ecoli Branching Enzyme with beta cyclodextrin [Escherichia coli O139:H28 str. E24377A],5E6Z_C Crystal structure of Ecoli Branching Enzyme with beta cyclodextrin [Escherichia coli O139:H28 str. E24377A],5E6Z_D Crystal structure of Ecoli Branching Enzyme with beta cyclodextrin [Escherichia coli O139:H28 str. E24377A],5E70_A Crystal structure of Ecoli Branching Enzyme with gamma cyclodextrin [Escherichia coli O139:H28 str. E24377A],5E70_B Crystal structure of Ecoli Branching Enzyme with gamma cyclodextrin [Escherichia coli O139:H28 str. E24377A],5E70_C Crystal structure of Ecoli Branching Enzyme with gamma cyclodextrin [Escherichia coli O139:H28 str. E24377A],5E70_D Crystal structure of Ecoli Branching Enzyme with gamma cyclodextrin [Escherichia coli O139:H28 str. E24377A]

TheX-ray Crystallographic Structure of Branching Enzyme [Escherichia coli],1M7X_B The X-ray Crystallographic Structure of Branching Enzyme [Escherichia coli],1M7X_C The X-ray Crystallographic Structure of Branching Enzyme [Escherichia coli],1M7X_D The X-ray Crystallographic Structure of Branching Enzyme [Escherichia coli]

Maltosyltransferasefrom Thermotoga maritima [Thermotoga maritima MSB8],1GJW_A Thermotoga maritima maltosyltransferase complex with maltose [Thermotoga maritima]

ChainA, Alpha-glycosidase [Weissella cibaria]

Alpha-amylase MalA OS=Haloarcula japonica (strain ATCC 49778 / DSM 6131 / JCM 7785 / NBRC 101032 / NCIMB 13157 / TR-1) OX=1227453 GN=malA PE=1 SV=1

1,4-alpha-glucan branching enzyme GlgB OS=Nitrobacter winogradskyi (strain ATCC 25391 / DSM 10237 / CIP 104748 / NCIMB 11846 / Nb-255) OX=323098 GN=glgB PE=3 SV=1

1,4-alpha-glucan branching enzyme GlgB 2 OS=Xanthomonas axonopodis pv. citri (strain 306) OX=190486 GN=glgB2 PE=3 SV=1

1,4-alpha-glucan branching enzyme GlgB 2 OS=Xanthomonas campestris pv. vesicatoria (strain 85-10) OX=316273 GN=glgB2 PE=3 SV=1

1,4-alpha-glucan branching enzyme GlgB 2 OS=Xanthomonas campestris pv. campestris (strain 8004) OX=314565 GN=glgB2 PE=3 SV=1