Amylo-alpha-1,6-glucosidase. This family includes human glycogen branching enzyme AGL. This enzyme contains a number of distinct catalytic activities. It has been shown for the yeast homolog GDB1 that mutations in this region disrupt the enzymes Amylo-alpha-1,6-glucosidase (EC:3.2.1.33).

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.

Glycogen debranching enzyme (alpha-1,6-glucosidase) [Carbohydrate transport and metabolism].

Alpha amylase catalytic domain found in GlgE-like proteins. GlgE is a (1,4)-a-D-glucan:phosphate a-D-maltosyltransferase, involved in a-glucan biosynthesis in bacteria. It is also an anti-tuberculosis drug target. GlgE isoform I from Streptomyces coelicolor has the same catalytic and very similar kinetic properties to GlgE from Mycobacterium tuberculosis. GlgE from Streptomyces coelicolor forms a homodimer with each subunit comprising five domains (A, B, C, N, and S) and 2 inserts. Domain A is a catalytic alpha-amylase-type domain that along with domain N, which has a beta-sandwich fold and forms the core of the dimer interface, binds cyclodextrins. Domain A, B, and the 2 inserts define a well conserved donor pocket that binds maltose. Cyclodextrins competitively inhibit the binding of maltooligosaccharides to the S. coelicolor enzyme, indicating that the hydrophobic patch overlaps with the acceptor binding site. This is not the case in M. tuberculosis GlgE because cyclodextrins do not inhibit this enzyme, despite acceptor length specificity being conserved. Domain C is hypothesized to help stabilize domain A and could be involved in substrate binding. Domain S is a helix bundle that is inserted within the N domain and it plays a role in the dimer interface and interacts directly with domain B. 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.

Crystalstructure of an alpha-amylase from Lactobacillus plantarum [Lactiplantibacillus plantarum],3DHU_B Crystal structure of an alpha-amylase from Lactobacillus plantarum [Lactiplantibacillus plantarum],3DHU_C Crystal structure of an alpha-amylase from Lactobacillus plantarum [Lactiplantibacillus plantarum],3DHU_D Crystal structure of an alpha-amylase from Lactobacillus plantarum [Lactiplantibacillus plantarum]

Crystalstructure of a noncanonic maltogenic alpha-amylase AmyB from Thermotoga neapolitana [Thermotoga neapolitana],4GKL_B Crystal structure of a noncanonic maltogenic alpha-amylase AmyB from Thermotoga neapolitana [Thermotoga neapolitana]

Structureof Mtb GlgE bound to maltose [Mycobacterium tuberculosis CDC1551],4U33_B Structure of Mtb GlgE bound to maltose [Mycobacterium tuberculosis CDC1551],4U33_C Structure of Mtb GlgE bound to maltose [Mycobacterium tuberculosis CDC1551],4U33_D Structure of Mtb GlgE bound to maltose [Mycobacterium tuberculosis CDC1551],4U33_E Structure of Mtb GlgE bound to maltose [Mycobacterium tuberculosis CDC1551],4U33_F Structure of Mtb GlgE bound to maltose [Mycobacterium tuberculosis CDC1551],4U3C_A Docking Site of Maltohexaose in the Mtb GlgE [Mycobacterium tuberculosis CDC1551],4U3C_B Docking Site of Maltohexaose in the Mtb GlgE [Mycobacterium tuberculosis CDC1551],4U3C_C Docking Site of Maltohexaose in the Mtb GlgE [Mycobacterium tuberculosis CDC1551],4U3C_D Docking Site of Maltohexaose in the Mtb GlgE [Mycobacterium tuberculosis CDC1551],4U3C_E Docking Site of Maltohexaose in the Mtb GlgE [Mycobacterium tuberculosis CDC1551],4U3C_F Docking Site of Maltohexaose in the Mtb GlgE [Mycobacterium tuberculosis CDC1551]

Structureof Mycobacterium thermoresistibile GlgE in complex with maltose at 1.95A resolution [Mycolicibacterium thermoresistibile ATCC 19527],5CGM_B Structure of Mycobacterium thermoresistibile GlgE in complex with maltose at 1.95A resolution [Mycolicibacterium thermoresistibile ATCC 19527],5CIM_A Structure of Mycobacterium thermoresistibile GlgE in complex with maltose (cocrystallisation with maltose-1-phosphate) at 3.32A resolution [Mycolicibacterium thermoresistibile ATCC 19527],5CIM_B Structure of Mycobacterium thermoresistibile GlgE in complex with maltose (cocrystallisation with maltose-1-phosphate) at 3.32A resolution [Mycolicibacterium thermoresistibile ATCC 19527],5CJ5_A Structure of Mycobacterium thermoresistibile GlgE APO form at 3.13A resolution [Mycolicibacterium thermoresistibile ATCC 19527],5CJ5_B Structure of Mycobacterium thermoresistibile GlgE APO form at 3.13A resolution [Mycolicibacterium thermoresistibile ATCC 19527]

ChainA, CYCLOMALTODEXTRIN GLUCANOTRANSFERASE [Niallia circulans]

Alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase OS=Rhodospirillum rubrum (strain ATCC 11170 / ATH 1.1.1 / DSM 467 / LMG 4362 / NCIMB 8255 / S1) OX=269796 GN=glgE PE=3 SV=1

Alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase OS=Burkholderia pseudomallei (strain K96243) OX=272560 GN=glgE PE=3 SV=2

Alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase OS=Pseudomonas aeruginosa (strain ATCC 15692 / DSM 22644 / CIP 104116 / JCM 14847 / LMG 12228 / 1C / PRS 101 / PAO1) OX=208964 GN=glgE PE=3 SV=1

Alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase OS=Myxococcus xanthus (strain DK1622) OX=246197 GN=glgE PE=3 SV=1

Alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase OS=Picrophilus torridus (strain ATCC 700027 / DSM 9790 / JCM 10055 / NBRC 100828) OX=263820 GN=glgE PE=3 SV=1