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 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.

Glycosidase [Carbohydrate transport and metabolism].

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 found in maltosyltransferase. Maltosyltransferase (MTase), a maltodextrin glycosyltransferase, acts on starch and maltooligosaccharides. It catalyzes the transfer of maltosyl units from alpha-1,4-linked glucans or maltooligosaccharides to other alpha-1,4-linked glucans, maltooligosaccharides or glucose. MTase is a homodimer. The catalytic core domain has the (beta/alpha) 8 barrel fold with the active-site cleft formed at the C-terminal end of the barrel. Substrate binding experiments have led to the location of two distinct maltose-binding sites: one lies in the active-site cleft and the other is located in a pocket adjacent to the active-site cleft. It is a member of the alpha-amylase family, but unlike typical alpha-amylases, MTase does not require calcium for activity and lacks two histidine residues which are predicted to be critical for binding the glucose residue adjacent to the scissile bond in the substrates. The common reaction chemistry of the alpha-amylase family of enzymes is based on a two-step acid catalytic mechanism that requires two critical carboxylates: one acting as a general acid/base (Glu) and the other as a nucleophile (Asp). Both hydrolysis and transglycosylation proceed via the nucleophilic substitution reaction between the anomeric carbon, C1 and a nucleophile. 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.

ScoGlgEI-V279S in Complex with Reaction Intermediate Azasugar [Streptomyces coelicolor A3(2)],4U2Y_B Sco GlgEI-V279S in Complex with Reaction Intermediate Azasugar [Streptomyces coelicolor A3(2)],4U2Z_A X-ray crystal structure of an Sco GlgEI-V279S/1,2,2-trifluromaltose complex [Streptomyces coelicolor A3(2)],4U2Z_B X-ray crystal structure of an Sco GlgEI-V279S/1,2,2-trifluromaltose complex [Streptomyces coelicolor A3(2)],4U31_A Sco GlgEI-V279S in Complex with maltose-C-phosphonate [Streptomyces coelicolor A3(2)],4U31_B Sco GlgEI-V279S in Complex with maltose-C-phosphonate [Streptomyces coelicolor A3(2)],7MEL_A Chain A, Alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase 1 [Streptomyces coelicolor A3(2)],7MEL_B Chain B, Alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase 1 [Streptomyces coelicolor A3(2)],7MGY_A Chain A, Alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase 1 [Streptomyces coelicolor A3(2)],7MGY_B Chain B, Alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase 1 [Streptomyces coelicolor A3(2)]

Apoform of GlgE isoform 1 from Streptomyces coelicolor [Streptomyces coelicolor],3ZSS_B Apo form of GlgE isoform 1 from Streptomyces coelicolor [Streptomyces coelicolor],3ZSS_C Apo form of GlgE isoform 1 from Streptomyces coelicolor [Streptomyces coelicolor],3ZSS_D Apo form of GlgE isoform 1 from Streptomyces coelicolor [Streptomyces coelicolor],3ZST_A GlgE isoform 1 from Streptomyces coelicolor with alpha-cyclodextrin bound [Streptomyces coelicolor],3ZST_B GlgE isoform 1 from Streptomyces coelicolor with alpha-cyclodextrin bound [Streptomyces coelicolor],3ZT5_A GlgE isoform 1 from Streptomyces coelicolor with maltose bound [Streptomyces coelicolor],3ZT5_B GlgE isoform 1 from Streptomyces coelicolor with maltose bound [Streptomyces coelicolor],3ZT5_C GlgE isoform 1 from Streptomyces coelicolor with maltose bound [Streptomyces coelicolor],3ZT5_D GlgE isoform 1 from Streptomyces coelicolor with maltose bound [Streptomyces coelicolor],3ZT6_A GlgE isoform 1 from Streptomyces coelicolor with alpha-cyclodextrin and maltose bound [Streptomyces coelicolor],3ZT6_B GlgE isoform 1 from Streptomyces coelicolor with alpha-cyclodextrin and maltose bound [Streptomyces coelicolor],3ZT6_C GlgE isoform 1 from Streptomyces coelicolor with alpha-cyclodextrin and maltose bound [Streptomyces coelicolor],3ZT6_D GlgE isoform 1 from Streptomyces coelicolor with alpha-cyclodextrin and maltose bound [Streptomyces coelicolor],3ZT7_A GlgE isoform 1 from Streptomyces coelicolor with beta-cyclodextrin and maltose bound [Streptomyces coelicolor],3ZT7_B GlgE isoform 1 from Streptomyces coelicolor with beta-cyclodextrin and maltose bound [Streptomyces coelicolor],3ZT7_C GlgE isoform 1 from Streptomyces coelicolor with beta-cyclodextrin and maltose bound [Streptomyces coelicolor],3ZT7_D GlgE isoform 1 from Streptomyces coelicolor with beta-cyclodextrin and maltose bound [Streptomyces coelicolor]

ScoGlgEI-V279S in complex with a pyrolidene-based ethyl-phosphonate compound [Streptomyces coelicolor A3(2)],5VSJ_B Sco GlgEI-V279S in complex with a pyrolidene-based ethyl-phosphonate compound [Streptomyces coelicolor A3(2)],5VT4_A Sco GlgEI-V279S in complex with a pyrolidene-based methyl-phosphonate compound [Streptomyces coelicolor A3(2)],5VT4_B Sco GlgEI-V279S in complex with a pyrolidene-based methyl-phosphonate compound [Streptomyces coelicolor A3(2)],5VT4_C Sco GlgEI-V279S in complex with a pyrolidene-based methyl-phosphonate compound [Streptomyces coelicolor A3(2)],5VT4_D Sco GlgEI-V279S in complex with a pyrolidene-based methyl-phosphonate compound [Streptomyces coelicolor A3(2)]

GlgEisoform 1 from Streptomyces coelicolor E423A mutant soaked in maltoheptaose [Streptomyces coelicolor],5CVS_B GlgE isoform 1 from Streptomyces coelicolor E423A mutant soaked in maltoheptaose [Streptomyces coelicolor]

GlgEisoform 1 from Streptomyces coelicolor E423A mutant with 2-deoxy- 2-fluoro-beta-maltosyl modification [Streptomyces coelicolor],4CN4_B GlgE isoform 1 from Streptomyces coelicolor E423A mutant with 2-deoxy- 2-fluoro-beta-maltosyl modification [Streptomyces coelicolor],4CN6_A GlgE isoform 1 from Streptomyces coelicolor E423A mutant with maltose bound [Streptomyces coelicolor],4CN6_B GlgE isoform 1 from Streptomyces coelicolor E423A mutant with maltose bound [Streptomyces coelicolor],5LGV_A GlgE isoform 1 from Streptomyces coelicolor E423A mutant soaked in maltooctaose [Streptomyces coelicolor A3(2)],5LGV_B GlgE isoform 1 from Streptomyces coelicolor E423A mutant soaked in maltooctaose [Streptomyces coelicolor A3(2)]

Alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase OS=Arcanobacterium haemolyticum (strain ATCC 9345 / DSM 20595 / CCUG 17215 / LMG 16163 / NBRC 15585 / NCTC 8452 / 11018) OX=644284 GN=glgE PE=3 SV=1

Alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase OS=Bifidobacterium longum (strain NCC 2705) OX=206672 GN=glgE PE=3 SV=1

Alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase 1 OS=Streptomyces coelicolor (strain ATCC BAA-471 / A3(2) / M145) OX=100226 GN=glgE1 PE=1 SV=1

Alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase 2 OS=Streptomyces coelicolor (strain ATCC BAA-471 / A3(2) / M145) OX=100226 GN=glgE2 PE=1 SV=1

Alpha-1,4-glucan:maltose-1-phosphate maltosyltransferase OS=Bifidobacterium animalis subsp. lactis (strain Bl-04 / DGCC2908 / RB 4825 / SD5219) OX=580050 GN=glgE PE=3 SV=1