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.

4-alpha-glucanotransferase; Provisional

bifunctional glycogen debranching protein GlgX/4-alpha-glucanotransferase.

4-alpha-glucanotransferase. These enzymes EC:2.4.1.25 transfer a segment of a (1,4)-alpha-D-glucan to a new 4-position in an acceptor, which may be glucose or (1,4)-alpha-D-glucan.

disproportionating enzyme

Aquifexaeolicus amylomaltase [Aquifex aeolicus],1TZ7_B Aquifex aeolicus amylomaltase [Aquifex aeolicus]

glycosidehydrolase family 77 4-alpha-glucanotransferase from thermus brockianus [Thermus brockianus]

Disproportionatingenzyme 1 from Arabidopsis - apo form [Arabidopsis thaliana],5CPQ_B Disproportionating enzyme 1 from Arabidopsis - apo form [Arabidopsis thaliana],5CPS_A Disproportionating enzyme 1 from Arabidopsis - maltotriose soak [Arabidopsis thaliana],5CPS_B Disproportionating enzyme 1 from Arabidopsis - maltotriose soak [Arabidopsis thaliana],5CPT_A Disproportionating enzyme 1 from Arabidopsis - beta cyclodextrin soak [Arabidopsis thaliana],5CPT_B Disproportionating enzyme 1 from Arabidopsis - beta cyclodextrin soak [Arabidopsis thaliana],5CQ1_A Disproportionating enzyme 1 from Arabidopsis - cycloamylose soak [Arabidopsis thaliana],5CQ1_B Disproportionating enzyme 1 from Arabidopsis - cycloamylose soak [Arabidopsis thaliana],5CSU_A Disproportionating enzyme 1 from Arabidopsis - acarviostatin soak [Arabidopsis thaliana],5CSU_B Disproportionating enzyme 1 from Arabidopsis - acarviostatin soak [Arabidopsis thaliana],5CSY_A Disproportionating enzyme 1 from Arabidopsis - acarbose soak [Arabidopsis thaliana],5CSY_B Disproportionating enzyme 1 from Arabidopsis - acarbose soak [Arabidopsis thaliana]

Structureof a covalent intermediate in Thermus thermophilus amylomaltase [Thermus thermophilus],2OWW_A Covalent intermediate in amylomaltase in complex with the acceptor analog 4-deoxyglucose [Thermus thermophilus],2OWX_A THERMUS THERMOPHILUS AMYLOMALTASE AT pH 5.6 [Thermus thermophilus]

Structuredetermination and refinement at 1.8 A resolution of Disproportionating Enzyme from Potato [Solanum tuberosum],6LX1_A Potato D-enzyme complexed with Acarbose [Solanum tuberosum],6LX2_A Potato D-enzyme complexed with CA26 [Solanum tuberosum]

Amylopullulanase OS=Thermoanaerobacterium saccharolyticum OX=28896 GN=apu PE=3 SV=2

Amylopullulanase OS=Thermoanaerobacter pseudethanolicus (strain ATCC 33223 / 39E) OX=340099 GN=apu PE=1 SV=2

Amylopullulanase OS=Thermoanaerobacterium thermosulfurigenes OX=33950 GN=amyB PE=3 SV=2

Amylopullulanase OS=Thermoanaerobacter thermohydrosulfuricus OX=1516 GN=apu PE=1 SV=1

4-alpha-glucanotransferase OS=Synechocystis sp. (strain PCC 6803 / Kazusa) OX=1111708 GN=malQ PE=3 SV=1