alpha-1,4-glucan 4-glycosyltransferase, cyclizing
neutral-cyclodextrin glycosyltransferase
1,4-alpha-D-glucan 4-alpha-D-(1,4-alpha-D-glucano)-transferase(cyclizing)
This enzyme belongs to the glycosidase family-13 (or family of alpha-amylase). Although this enzyme binds two calcium ions on the catalytic domain, they are not involved in catalytic reaction. According to the literature [20], [31], [34], [35], [36] & [39], the reaction proceeds as follows: (1) Asp328 (and/or His327) modulate(s) the activity of Glu257 by raising its pKa, so that the carboxylate of Glu257 is protonated to act as a general acid. (2) Glu257 acts as a general acid, to protonate the leaving O4 atom, leading to the formation of oxocarbonium transition-state (SN1-like reaction). This transition state is stabilized by Asp328 and His327. (3) Asp229 acts as a nucleophile, attacking the C1 atom to form a covalent bond with it, which is an intermediate. (4) The acceptor group, O4 hydroxyl group of the non-reducing end, approaches the active site. (5) Glu257 acts as a general base to deprotonate the acceptor, O4 hydroxyl group. (6) The O4 hydroxyl group makes a nucleophilic attack on the C1 atom, leading to the formation of oxocarbonium transition-state (SN1-like reaction). This transition state is stabilized by Asp328 and His327. (7) Finally, Asp229 is releaased.
Crystallization of and preliminary crystallographic data for Bacillus stearothermophilus cyclodextrin glucanotransferase.
Catalytic center of cyclodextrin glycosyltransferase derived from X-ray structure analysis combined with site-directed mutagenesis.
Four aromatic residues in the active center of cyclodextrin glucanotransferase from alkalophilic Bacillus sp. 1011: effects of replacements on substrate binding and cyclization characteristics.
Replacement of an amino acid residue of cyclodextrin glucanotransferase of Bacillus ohbensis doubles the production of gamma-cyclodextrin.
Crystallization and preliminary X-ray studies of cyclodextrin glucanotransferase from alkalophilic Bacillus sp. 1011.
Nucleotide sequence and X-ray structure of cyclodextrin glycosyltransferase from Bacillus circulans strain 251 in a maltose-dependent crystal form.
Protein engineering in the alpha-amylase family: catalytic mechanism, substrate specificity, and stability.
Characteristic differences in the primary structure allow discrimination of cyclodextrin glucanotransferases from alpha-amylases.
Site-directed mutations in tyrosine 195 of cyclodextrin glycosyltransferase from Bacillus circulans strain 251 affect activity and product specificity.
Determination of the catalytic activity of cyclomaltodextrin glucanotransferase by maltotriose-methylorange assay.
Implications for the catalytic mechanism of glycosidases.
Dijkstra BW. X-ray structure of cyclodextrin glycosyltransferase complexed with acarbose
Crystallographic studies of the interaction of cyclodextrin glycosyltransferase from Bacillus circulans strain 251 with natural substrates and products.
X-ray structure of cyclodextrin glucanotransferase from alkalophilic Bacillus Sp. 1011. Comparison of two independent molecules at 1.8-A resolution.
Structure of cyclodextrin glycosyltransferase complexed with a maltononaose inhibitor at 2.6 angstrom resolution. Implications for product specificity.
X-RAY CRYSTALLOGRAPHY (2.6 ANGSTROMS) OF COMPLEX WITH INHIBITOR.
The raw starch binding domain of cyclodextrin glycosyltransferase from Bacillus circulans strain 251.
Crystal structure at 2.3 A resolution and revised nucleotide sequence of the thermostable cyclodextrin glycosyltransferase from Thermonanaerobacterium thermosulfurigenes EM1.
alpha-Amylase family: molecular biology and evolution.
Reassessment of acarbose as a transition state analogue inhibitor of cyclodextrin glycosyltransferase.
Structure of cyclodextrin glycosyltransferase complexed with a derivative of its main product beta-cyclodextrin.
Substrate binding to a cyclodextrin glycosyltransferase and mutations increasing the gamma-cyclodextrin production.
A super-secondary structure predicted to be common to several alpha-1,4-D-glucan-cleaving enzymes.
Engineering of factors determining alpha-amylase and cyclodextrin glycosyltransferase specificity in the cyclodextrin glycosyltransferase from Thermoanaerobacterium thermosulfurigenes EM1.
Engineering of cyclodextrin product specificity and pH optima of the thermostable cyclodextrin glycosyltransferase from Thermoanaerobacterium thermosulfurigenes EM1.
Effects of mutations in the starch-binding domain of Bacillus macerans cyclodextrin glycosyltransferase.
Chemical modification of lysine side chains of cyclodextrin glycosyltransferase from Thermoanaerobacter causes a shift from cyclodextrin glycosyltransferase to alpha-amylase specificity.
The cyclization mechanism of cyclodextrin glycosyltransferase (CGTase) as revealed by a gamma-cyclodextrin-CGTase complex at 1.8-A resolution.
X-ray structures along the reaction pathway of cyclodextrin glycosyltransferase elucidate catalysis in the alpha-amylase family.
Introduction of raw starch-binding domains into Bacillus subtilis alpha-amylase by fusion with the starch-binding domain of Bacillus cyclomaltodextrin glucanotransferase.
Structures of maltohexaose and maltoheptaose bound at the donor sites of cyclodextrin glycosyltransferase give insight into the mechanisms of transglycosylation activity and cyclodextrin size specificity.
Engineering of cyclodextrin glycosyltransferase reaction and product specificity.
Three-dimensional structure of cyclodextrin glycosyltransferase from Bacillus circulans at 3.4 A resolution.
The three transglycosylation reactions catalyzed by cyclodextrin glycosyltransferase from Bacillus circulans (strain 251) proceed via different kinetic mechanisms.
Crystal structure of alkalophilic asparagine 233-replaced cyclodextrin glucanotransferase complexed with an inhibitor, acarbose, at 2.0 A resolution.
Rational design of cyclodextrin glycosyltransferase from Bacillus circulans strain 251 to increase alpha-cyclodextrin production.
Crystal structure of asparagine 233-replaced cyclodextrin glucanotransferase from alkalophilic Bacillus sp. 1011 determined at 1.9 A resolution.
Trapping of a covalent enzyme intermediate in the reaction of Bacillus macerans cyclomaltodextrin glucanyltransferase with cyclomaltohexaose.
Crystal structure of cyclodextrin glucanotransferase from alkalophilic Bacillus sp. 1011 complexed with 1-deoxynojirimycin at 2.0 A resolution.
Hydrophobic amino acid residues in the acceptor binding site are main determinants for reaction mechanism and specificity of cyclodextrin-glycosyltransferase.
Enzymatic circularization of a malto-octaose linear chain studied by stochastic reaction path calculations on cyclodextrin glycosyltransferase.
Mutations converting cyclodextrin glycosyltransferase from a transglycosylase into a starch hydrolase.
Modulation of cyclizing activity and thermostability of cyclodextrin glucanotransferase and its application as an antistaling enzyme.
Maltodextrin-dependent crystallization of cyclomaltodextrin glucanotransferase from Bacillus circulans.
Characterization of an archaeal cyclodextrin glucanotransferase with a novel C-terminal domain.
The remote substrate binding subsite -6 in cyclodextrin-glycosyltransferase controls the transferase activity of the enzyme via an induced-fit mechanism.
Crystallization and preliminary X-ray diffraction studies of alpha-cyclodextrin glucanotransferase isolated from Bacillus macerans.
Conversion of cyclodextrin glycosyltransferase into a starch hydrolase by directed evolution: the role of alanine 230 in acceptor subsite +1.
The fully conserved Asp residue in conserved sequence region I of the alpha-amylase family is crucial for the catalytic site architecture and activity.
Effects of essential carbohydrate/aromatic stacking interaction with Tyr100 and Phe259 on substrate binding of cyclodextrin glycosyltransferase from alkalophilic Bacillus sp. 1011.
Engineering cyclodextrin glycosyltransferase into a starch hydrolase with a high exo-specificity.
Crystal structure of the covalent intermediate of amylosucrase from Neisseria polysaccharea.
Single amino acid mutations interchange the reaction specificities of cyclodextrin glycosyltransferase and the acarbose-modifying enzyme acarviosyl transferase.
Improvement of cyclodextrin glucanotransferase as an antistaling enzyme by error-prone PCR.
Engineering a heavy atom derivative for the X-ray structure analysis of cyclodextrin glycosyltransferase.
Role of Phe283 in enzymatic reaction of cyclodextrin glycosyltransferase from alkalophilic Bacillus sp.1011: Substrate binding and arrangement of the catalytic site.
Improved thermostability of bacillus circulans cyclodextrin glycosyltransferase by the introduction of a salt bridge.
Investigation of the active site of Bacillus macerans cyclodextrin glucanotransferase by use of modified maltooligosaccharides.
Structure of cyclodextrin glycosyltransferase refined at 2.0 A resolution.
The transglycosylation reaction of cyclodextrin glucanotransferase is operated by a Ping-Pong mechanism.
Cyclodextrin formation by the thermostable alpha-amylase of Thermoanaerobacterium thermosulfurigenes EM1 and reclassification of the enzyme as a cyclodextrin glycosyltransferase.
Cyclization characteristics of cyclodextrin glucanotransferase are conferred by the NH2-terminal region of the enzyme.
ASP 27;ASN 29;ASN 32;ASN 33;GLY 51;ASP 53(Calcium-1);ASN 139;ILE 190;ASP 199;HIS 233(Calcium-2)
ASP 27;ASN 29;ASN 32;ASN 33;GLY 51;ASP 53(Calcium-1);ASN 140;ILE 191;ASP 200;HIS 234(Calcium-2)
ASP 24;ASN 26;ASN 29;ASN 30;GLY 48;ASP 50(Calcium-1);ASN 135;ILE 186;ASP 195;HIS 229(Calcium-2)
ASP 27;ASN 29;ASN 32;ASN 33;GLY 51;ASP 53(Calcium-1);ASN 139;ILE 190;ASP 199; (Calcium-2)