alpha-amylase; Reviewed

Carbohydrate binding domain (family 25).

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.

Starch-binding module 26. CBM26 is a carbohydrate-binding module that binds starch.

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.

ChainA, ALPHA-AMYLASE G-6 [Halalkalibacterium halodurans C-125],2C3H_A Chain A, ALPHA-AMYLASE G-6 [Halalkalibacterium halodurans],2C3H_B Chain B, ALPHA-AMYLASE G-6 [Halalkalibacterium halodurans],2C3H_C Chain C, ALPHA-AMYLASE G-6 [Halalkalibacterium halodurans],2C3H_D Chain D, ALPHA-AMYLASE G-6 [Halalkalibacterium halodurans],2C3H_E Chain E, ALPHA-AMYLASE G-6 [Halalkalibacterium halodurans],2C3H_F Chain F, ALPHA-AMYLASE G-6 [Halalkalibacterium halodurans],2C3H_G Chain G, ALPHA-AMYLASE G-6 [Halalkalibacterium halodurans],2C3H_H Chain H, ALPHA-AMYLASE G-6 [Halalkalibacterium halodurans]

SolutionStrucuture of the CBM25-1 of beta/alpha-amylase from Paenibacillus polymyxa [Paenibacillus polymyxa]

SolutionStrucuture of the CBM25-2 of beta/alpha-amylase from Paenibacillus polymyxa [Paenibacillus polymyxa]

ChainA, CHITINASE A1 [Niallia circulans]

ChainB, ALPHA-AMYLASE G-6 [Halalkalibacterium halodurans C-125],2C3W_A Chain A, ALPHA-AMYLASE G-6 [Halalkalibacterium halodurans C-125],2C3W_B Chain B, ALPHA-AMYLASE G-6 [Halalkalibacterium halodurans C-125],2C3W_C Chain C, ALPHA-AMYLASE G-6 [Halalkalibacterium halodurans C-125],2C3W_D Chain D, ALPHA-AMYLASE G-6 [Halalkalibacterium halodurans C-125],2C3X_A Chain A, Alpha-amylase G-6 [Halalkalibacterium halodurans C-125],2C3X_B Chain B, Alpha-amylase G-6 [Halalkalibacterium halodurans C-125]

Periplasmic alpha-amylase OS=Escherichia coli (strain K12) OX=83333 GN=malS PE=1 SV=1

Alpha-amylase OS=Niallia circulans OX=1397 GN=igtZ PE=1 SV=1

Beta/alpha-amylase OS=Paenibacillus polymyxa OX=1406 PE=1 SV=1

Beta-amylase OS=Niallia circulans OX=1397 PE=3 SV=1

Chitinase A1 OS=Niallia circulans OX=1397 GN=chiA1 PE=1 SV=1