Crystal Structure at 2.3 Å Resolution and Revised Nucleotide Sequence of the Thermostable Cyclodextrin Glycosyltransferase fromThermoanaerobacterium thermosulfurigenesEM1

Knegtel, Ronald M.A.; Wind, Richèle D.; Rozeboom, H.J.; Kalk, Kor H.; Buitelaar, R.M.; Dijkhuizen, Lubbert; Dijkstra, Bauke W.

doi:10.1006/jmbi.1996.0113

Cited by 80 publications

(71 citation statements)

References 40 publications

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“…Thus, a comparison of CGTase with amylomaltase should provide various useful pieces of information. In addition to the structure of CGTases (3,6,7,12,14), the crystal structure of amylomaltase from T. aquaticus (19) has recently become available. These results should contribute to our understanding of the actions of these enzymes.…”

Section: Discussionmentioning

confidence: 99%

Comparative Study of the Cyclization Reactions of Three Bacterial Cyclomaltodextrin Glucanotransferases

Terada

Sanbe

Takaha

et al. 2001

Appl Environ Microbiol

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The actions of cyclomaltodextrin glucanotransferases (CGTase; EC 2.4.1.19) from alkalophilic Bacillus sp. strain A2-5a (A2-5a CGTase), Bacillus macerans (Bmac CGTase), and Bacillus stearothermophilus (Bste CGTase) on amylose were investigated. All three enzymes produced large cyclic ␣-1,4-glucans (cycloamyloses) at the early stage of the reaction, but these were subsequently converted into smaller cycloamyloses. However, the rates of this conversion differed among the three enzymes. The product specificity of each CGTase in the cyclization reaction was determined by measuring the amount of each cycloamylose from CD6 to CD31 (CDn, a cycloamylose with a degree of polymerization of n). A2-5a CGTase produced 10 times more CD7, while Bmac CGTase produced 34 times more CD6 than other cycloamyloses. Bste CGTase produced 12 and 3 times more CD6 and CD7 than other cycloamyloses, respectively. The substrate specificities of the linearization reactions of CD6, CD7, CD8, and larger cycloamyloses (a mixture of CD22 to CD50) were investigated, and we found that CD7 and CD8 are extremely poor substrates for both hydrolytic and transglycosidic linearization (coupling) reactions while larger cycloamyloses are linearized at a much higher rate. By repeating these cyclization and linearization reactions, the larger cycloamyloses initially produced are converted into smaller cycloamyloses and finally into mainly CD6, CD7, and CD8. These three enzymes also differ in their hydrolytic activities, which seem to accelerate the conversion of larger cycloamyloses into smaller cycloamyloses.

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Section: Discussionmentioning

confidence: 99%

Comparative Study of the Cyclization Reactions of Three Bacterial Cyclomaltodextrin Glucanotransferases

Terada

Sanbe

Takaha

et al. 2001

Appl Environ Microbiol

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“…Three-dimensional structures of several GH13 family enzymes, including α-amylases (Matsuura et al 1984;Brady et al 1991;Qian et al 1993;Kadziola et al 1994;Brayer et al 1995;Machius et al 1995;Ramasubbu et al 1996), cyclodextrin glucanotransferases (Klein & Schulz 1991;Kubota et al 1991;Lawson et al 1994;Knegtel et al 1996), and oligo-1,6-glucosidase (Kizaki et al 1993;Watanabe et al 1997) are already available. Collectively, family GH13 enzymes have certain criteria of evolution conservatory: (1) a very low degree of sequence similarities, located at or near strands β2, β3, β4, β5, and β7, and at a short region close to the C-terminus of domain B, serving as fingerprints (Kizaki et al 1993;Knegtel et al 1996); (2) an insertion of domain B between strand β3 and helix α3 of the catalytic (β/α) 8 -barrel (MacGregor 1993;Janeček 1994;Svensson 1994); and (3) three fully conserved catalytic residues Asp206, Glu230, and Asp297 (numbering as in Taka-amylase A) Strokopytov et al 1995).…”

Section: Introductionmentioning

confidence: 99%

Identification of critical amino acid residues for chloride binding of Bacillus licheniformis trehalose-6-phosphate hydrolase

et al. 2013

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Based on sequence alignment of selected Cl − dependent and independent glycoside hydrolase family 13 enzymes, two invariant residues (Arg201 and Asn347) and one tyrosine (Tyr365) that might be responsible for the binding of Bacillus licheniformis trehalose-6-phosphate hydrolase (Bl TreA) to chloride ion were identified. The role of these three residues was further explored by mutational and biophysical analyses. The mutant enzymes (R201Q/E/K, N327Q/D/K, and Y365A/R) and Bl TreA were individually overexpressed in Escherichia coli M15 host cells and purified by one-step nickel affinity chromatography on Ni-NTA resin. The purified Bl TreA and Y365A had a specific activity of 236.9 and 47.6 U/mg protein, respectively. The remaining enzymes lost their hydrolase activity completely even in the presence of high salt. With the exception of Y365A, all mutant enzymes did not have the ability to bind fluoride, chloride and nitrate anions. Structural analyses showed that the circular dichroism spectra of the mutant proteins were consistent with those of Bl TreA. However, wild-type and mutant enzymes displayed a slight difference in the profiles of intrinsic tryptophan fluorescence. Collectively, these results clearly indicate that Arg201 and Agr327 residues might play an essential role in chloride binding of Bl TreA.

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“…However, efficient CD production using whole-cell biotransformation has not been achieved so far. The composition of the CD products obtained by a CGTase synthesis reaction is determined primarily by the type of the enzyme employed and can be manipulated by addition of complexing agents or organic solvents to the reaction mixture (3, 27).CGTases catalyze transglycosylation reactions, which include cyclization, coupling, and disproportionation reactions, as well as a hydrolysis reaction (10,11,18,31,34). The disproportionation and hydrolytic reactions produce glucose and maltose besides the oligosaccharides.…”

mentioning

confidence: 99%

“…CGTases catalyze transglycosylation reactions, which include cyclization, coupling, and disproportionation reactions, as well as a hydrolysis reaction (10,11,18,31,34). The disproportionation and hydrolytic reactions produce glucose and maltose besides the oligosaccharides.…”

mentioning

confidence: 99%

Engineering of Cyclodextrin Glucanotransferase on the Cell Surface ofSaccharomyces cerevisiaefor Improved Cyclodextrin Production

Wang

2006

Appl Environ Microbiol

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The cyclodextrin glucanotransferase (CGTase) gene (cgt) from Bacillus circulans 251 was cloned into plasmid pYD1, which allowed regulated expression, secretion, and detection. The expression of CGTase with a-agglutinin at the N-terminal end on the extracellular surface of Saccharomyces cerevisiae was confirmed by immunofluorescence microscopy. This surface-anchored CGTase gave the yeast the ability to directly utilize starch as a sole carbon source and the ability to produce the anticipated products, cyclodextrins, as well as glucose and maltose. The resulting glucose and maltose, which are efficient acceptors in the CGTase coupling reaction, could be consumed by yeast fermentation and thus facilitated cyclodextrin production. On the other hand, ethanol produced by the yeast may form a complex with cyclodextrin and shift the equilibrium in favor of cyclodextrin production. The yeast with immobilized CGTase produced 24.07 mg/ml cyclodextrins when it was incubated in yeast medium supplemented with 4% starch. The production of CDs by CGTase is an important industrial process, and it has been reviewed by many authors (2,12,26,28). The CD production process is normally divided into two processes. The solvent process that is commonly used requires an organic complexing reagent to precipitate a specific CD selectively and to obtain one main product, while the nonsolvent process does not require a complexing reagent and results in a mixture of CDs. The addition of debranching enzymes (e.g., pullulanases and isoamylases) before the actual enzymatic CD production process can increase the yield by 4 to 6% (4,7,27). CDs are also produced by immobilized CGTase, which enables reuse of the enzyme (30). However, efficient CD production using whole-cell biotransformation has not been achieved so far. The composition of the CD products obtained by a CGTase synthesis reaction is determined primarily by the type of the enzyme employed and can be manipulated by addition of complexing agents or organic solvents to the reaction mixture (3, 27).CGTases catalyze transglycosylation reactions, which include cyclization, coupling, and disproportionation reactions, as well as a hydrolysis reaction (10,11,18,31,34). The disproportionation and hydrolytic reactions produce glucose and maltose besides the oligosaccharides. Glucose and maltose are efficient acceptors of the CGTase coupling reaction, and they react with CDs to form linear oligosaccharides and thus affect the formation of CDs. Lima et al. (20) proposed a CD production process in which the CGTase synthesis reaction is combined with yeast fermentation. The yeast consumes the glucose and maltose, which are produced during CD production by CGTase, while the ethanol produced by the yeast increases the yield of CDs by forming inclusion complexes with CDs, which are inhibitors of CGTase (19). CGTases have also been employed to produce high yields of large-ring CDs by adjusting the reaction conditions to prevent conversion of these CDs to small CDs (25,32).In this study, we set up a novel...

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Crystal Structure at 2.3 Å Resolution and Revised Nucleotide Sequence of the Thermostable Cyclodextrin Glycosyltransferase fromThermoanaerobacterium thermosulfurigenesEM1

Cited by 80 publications

References 40 publications

Comparative Study of the Cyclization Reactions of Three Bacterial Cyclomaltodextrin Glucanotransferases

Comparative Study of the Cyclization Reactions of Three Bacterial Cyclomaltodextrin Glucanotransferases

Identification of critical amino acid residues for chloride binding of Bacillus licheniformis trehalose-6-phosphate hydrolase

Engineering of Cyclodextrin Glucanotransferase on the Cell Surface ofSaccharomyces cerevisiaefor Improved Cyclodextrin Production

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