Application | Comment | Organism |
---|---|---|
synthesis | enzyme PcDTE is used industrially to produce D-psicose from the more abundant sugar D-fructose | Pseudomonas cichorii |
Cloned (Comment) | Organism |
---|---|
gene dte, recombinant expression of C-terminally His-tagged wild-type and mutant enzymes in Escherichia coli strain JM109 | Pseudomonas cichorii |
Crystallization (Comment) | Organism |
---|---|
recombinant enzyme mutant PcDTE_C66S in complexes with four deoxy rare sugars, 6-deoxy L-psicose, 1-deoxy 3-keto D-galactitol, 1-deoxy D-tagatose, and 1-deoxy L-tagatose, and with L-erythrulose (a sugar without groups at the 5- and 6-positions), hanging drop vapor diffusion method, mixing of 0.002 ml of 6-7 mg/ml protein in 5 mM Tris-HCl, pH 8.0, with 0.002 ml of reservoir solution containing 6.0-11.0 % w/v PEG 4000 and 100 mM CH3COONa, pH 4.6, and equilibration against 0.45 ml of reservoir solution, microgravity, X-ray diffraction structure determination and analysis at 1.59-2.3 A resolution, molecular replacement using crystal structure, PDB ID 1QUL, as a search model | Pseudomonas cichorii |
Protein Variants | Comment | Organism |
---|---|---|
C66S | site-directed mutagenesis, the enzyme mutant recognizes deoxy sugars as substrates. In PcDTE_C66S/deoxy sugar complex structures, bound ligand molecules in both the linear and ring forms are detected in the hydrophobic groove, while bound ligand molecules in the catalytic site are in the linear form | Pseudomonas cichorii |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Co2+ | activates, best metal ion | Pseudomonas cichorii | |
Mn2+ | activates | Pseudomonas cichorii | |
additional information | metal enzyme, divalent cations are required for activity | Pseudomonas cichorii |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
D-fructose | Pseudomonas cichorii | - |
D-psicose | - |
r | |
D-tagatose | Pseudomonas cichorii | - |
D-sorbose | - |
r |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Pseudomonas cichorii | O50580 | - |
- |
Purification (Comment) | Organism |
---|---|
recombinant C-terminally His-tagged wild-type and mutant enzymes from Escherichia coli strain JM109 by nickel affinity chromatography and ultrafiltration | Pseudomonas cichorii |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
0.127 | - |
recombinant enzyme mutant C66S, substrate 1-deoxy D-sorbose, pH 9.0, 60°C | Pseudomonas cichorii |
0.15 | - |
recombinant enzyme mutant C66S, substrate 1-deoxy L-sorbose, pH 9.0, 60°C | Pseudomonas cichorii |
7.6 | - |
recombinant enzyme mutant C66S, substrate 1-deoxy 3-keto D-allitol, pH 9.0, 60°C | Pseudomonas cichorii |
16.9 | - |
recombinant enzyme mutant C66S, substrate 6-deoxy L-fructose, pH 9.0, 60°C | Pseudomonas cichorii |
108 | - |
recombinant enzyme mutant C66S, substrate D-tagatose, pH 9.0, 60°C | Pseudomonas cichorii |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
1-deoxy 3-keto D-galactitol | 7% activity compared to the activity with D-tagatose | Pseudomonas cichorii | 1-deoxy 3-keto D-allitol | - |
r | |
1-deoxy D-tagatose | 0.12% activity compared to the activity with D-tagatose | Pseudomonas cichorii | 1-deoxy D-sorbose | - |
r | |
1-deoxy L-tagatose | 0.14% activity compared to the activity with D-tagatose | Pseudomonas cichorii | 1-deoxy L-sorbose | - |
r | |
6-deoxy L-psicose | 15.7% activity compared to the activity with D-tagatose | Pseudomonas cichorii | 6-deoxy L-fructose | - |
r | |
D-fructose | - |
Pseudomonas cichorii | D-psicose | - |
r | |
D-tagatose | - |
Pseudomonas cichorii | D-sorbose | - |
r | |
additional information | D-tagatose 3-epimerase (PcDTE) has a broad substrate specificity, it efficiently catalyzes the epimerization of not only D-tagatose to D-sorbose but also D-fructose to D-psicose (D-allulose) and also recognizes the deoxy sugars as substrates. Substrate recognition by the enzyme at the 1-, 2-, and 3-positions is responsible for enzymatic activity and substrate-enzyme interactions at the 4-, 5-, and 6-positions are not essential for the catalytic reaction of the enzyme leading to the broad substrate specificity of PcDTE. 1-Deoxy sugars may bind to the catalytic site in the inhibitor-binding mode. Ligand-binding structure at the catalytic site, overview. Binding structures of 6-deoxy L-psicose, 1-deoxy-3-oxo-D-galactitol, 1-deoxy-D-tagatose, 1-deoxy L-tagatose, L-erythrulose, D-talitol, and glycerol | Pseudomonas cichorii | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
DTE | - |
Pseudomonas cichorii |
PcDTE | - |
Pseudomonas cichorii |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
60 | - |
assay at | Pseudomonas cichorii |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
9 | - |
assay at | Pseudomonas cichorii |
General Information | Comment | Organism |
---|---|---|
evolution | the enzyme belongs to the D-tagatose 3-epimerase (D-TE) family | Pseudomonas cichorii |
additional information | the hydrophobic groove that acts as an accessible surface for substrate binding is formed through the dimerization of PcDTE. The sugar-ring opening of a substrate may occur in the hydrophobic groove and also that the narrow channel of the passageway to the catalytic site allows a substrate in the linear form to pass through. Ligand-binding structure at the catalytic site, overview | Pseudomonas cichorii |
physiological function | D-tagatose 3-epimerase (DTE) catalyzes epimerization between D-tagatose and D-sorbose. DTE from Pseudomonas cichorii (PcDTE) has a broad substrate specificity and efficiently catalyzes the epimerization of not only D-tagatose to D-sorbose but also D-fructose to D-psicose (D-allulose) | Pseudomonas cichorii |