Cloned (Comment) | Organism |
---|---|
gene AH68_00255, sequence comparisons and phylogenetic analysis, recombinant expression of His6-tagged enzyme in Escherichia coli strain BL21(DE3) | Bifidobacterium catenulatum subsp. kashiwanohense |
Crystallization (Comment) | Organism |
---|---|
enzyme in complex with pyridoxal 5'-phosphate and glutamate, hanging-drop vapor diffusion method, mixing of 15 mg/ml protein solution with reservoir solution containing 0.1 M MES, pH 5.0, 0.2 M ammonium chloride, 20% w/v PEG 6000, 0.5 mM PLP, and 100 mM glutamate, X-ray diffraction structure determination and analysis at 2.7 A resolution | Bifidobacterium catenulatum subsp. kashiwanohense |
Protein Variants | Comment | Organism |
---|---|---|
D154A | site-directed mutagenesis | Bifidobacterium catenulatum subsp. kashiwanohense |
R156A | site-directed mutagenesis | Bifidobacterium catenulatum subsp. kashiwanohense |
W21A | site-directed mutagenesis | Bifidobacterium catenulatum subsp. kashiwanohense |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
taurine-PLP aldimine | induced fit docking modelling. Lys279, a key residue in the pocket, is the receptor box center | Bifidobacterium catenulatum subsp. kashiwanohense |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
1.1 | - |
taurine | pH 7.2, 37°C, recombinant enzyme | Bifidobacterium catenulatum subsp. kashiwanohense | |
1.8 | - |
2-oxoglutarate | pH 7.2, 37°C, recombinant enzyme | Bifidobacterium catenulatum subsp. kashiwanohense |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
109700 | - |
recombinant enzyme, gel filtration | Bifidobacterium catenulatum subsp. kashiwanohense |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
taurine + 2-oxoglutarate | Bifidobacterium catenulatum subsp. kashiwanohense | 2-oxoglutarate is the physiological acceptor | 2-sulfoacetaldehyde + L-glutamate | - |
? | |
taurine + 2-oxoglutarate | Bifidobacterium catenulatum subsp. kashiwanohense PV20-2 | 2-oxoglutarate is the physiological acceptor | 2-sulfoacetaldehyde + L-glutamate | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Bifidobacterium catenulatum subsp. kashiwanohense | A0A0A7I435 | isolated from human infant feces | - |
Bifidobacterium catenulatum subsp. kashiwanohense PV20-2 | A0A0A7I435 | isolated from human infant feces | - |
Purification (Comment) | Organism |
---|---|
recombinant His6-tagged enzyme from Escherichia coli strain BL21(DE3) by nickel affinity chromatography, the tag is cleaved off by TEV protease, followed by another step of nickel affinity chromatography, dialysis, and anion exchange chromatography | Bifidobacterium catenulatum subsp. kashiwanohense |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | in the enzyme complex crystal structure, two glutamate molecules are bound in sites near the predicted active site and they may occupy a path for substrate entry and product release | Bifidobacterium catenulatum subsp. kashiwanohense | ? | - |
- |
|
additional information | in the enzyme complex crystal structure, two glutamate molecules are bound in sites near the predicted active site and they may occupy a path for substrate entry and product release | Bifidobacterium catenulatum subsp. kashiwanohense PV20-2 | ? | - |
- |
|
taurine + 2-oxoglutarate | 2-oxoglutarate is the physiological acceptor | Bifidobacterium catenulatum subsp. kashiwanohense | 2-sulfoacetaldehyde + L-glutamate | - |
? | |
taurine + 2-oxoglutarate | the enzyme BkToa from Bifidobacterium kashiwanohense shows high specificity for 2-oxoglutarate as the amine acceptor, pyruvate does not function as acceptor | Bifidobacterium catenulatum subsp. kashiwanohense | 2-sulfoacetaldehyde + L-glutamate | - |
? | |
taurine + 2-oxoglutarate | 2-oxoglutarate is the physiological acceptor | Bifidobacterium catenulatum subsp. kashiwanohense PV20-2 | 2-sulfoacetaldehyde + L-glutamate | - |
? | |
taurine + 2-oxoglutarate | the enzyme BkToa from Bifidobacterium kashiwanohense shows high specificity for 2-oxoglutarate as the amine acceptor, pyruvate does not function as acceptor | Bifidobacterium catenulatum subsp. kashiwanohense PV20-2 | 2-sulfoacetaldehyde + L-glutamate | - |
? |
Subunits | Comment | Organism |
---|---|---|
homodimer | 2 * 49600, about, sequence calculation | Bifidobacterium catenulatum subsp. kashiwanohense |
More | each monomer exhibits a typical type I PLP-enzyme fold and conserved PLP-coordinating residues interacting with the pyridoxal 5'-phosphate (PLP) molecule | Bifidobacterium catenulatum subsp. kashiwanohense |
Synonyms | Comment | Organism |
---|---|---|
BkToa | - |
Bifidobacterium catenulatum subsp. kashiwanohense |
taurine:2-oxoglutarate aminotransferase | - |
Bifidobacterium catenulatum subsp. kashiwanohense |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
22 | - |
assay at room temperature | Bifidobacterium catenulatum subsp. kashiwanohense |
35 | - |
coupled assay with glutamate dehydrogenase/alanine dehydrogenase | Bifidobacterium catenulatum subsp. kashiwanohense |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
3.7 | - |
2-oxoglutarate | pH 7.2, 37°C, recombinant enzyme | Bifidobacterium catenulatum subsp. kashiwanohense | |
3.7 | - |
taurine | pH 7.2, 37°C, recombinant enzyme | Bifidobacterium catenulatum subsp. kashiwanohense |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
8 | - |
- |
Bifidobacterium catenulatum subsp. kashiwanohense |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
pyridoxal 5'-phosphate | each monomer of the homodimeric enzyme exhibits a typical type I PLP-enzyme fold and conserved PLP-coordinating residues interacting with the pyridoxal 5'-phosphate (PLP) molecule, binding structure in the active site, modelling, overview | Bifidobacterium catenulatum subsp. kashiwanohense |
General Information | Comment | Organism |
---|---|---|
evolution | sequence comparisons and phylogenetic analysis of taurine:oxoglutarate aminotransferases and taurine:pyruvate aminotransferases, overview | Bifidobacterium catenulatum subsp. kashiwanohense |
metabolism | BkToa is part of a gene cluster putatively involved in taurine nitrogen assimilation. In this pathway, isothionate is formed by a sulfoacetaldehyde reductase TauF, a member of the metal-dependent alcohol dehydrogenase family | Bifidobacterium catenulatum subsp. kashiwanohense |
additional information | molecular docking reveals a role for active site residues Trp21 and Arg156, conserved in Toa enzymes, in interacting with the sulfonate group of taurine | Bifidobacterium catenulatum subsp. kashiwanohense |
physiological function | taurine is thought to serve as a source of carbon, nitrogen and sulfur for certain gut bacteria, particularly for strict anaerobes residing in the nutrient-poor environment of the distal gut. Taurine aminotransferases catalyze the first step in taurine catabolism in many taurine-degrading bacteria and play an important role in bacterial taurine metabolism in the mammalian gut | Bifidobacterium catenulatum subsp. kashiwanohense |
kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
2.06 | - |
2-oxoglutarate | pH 7.2, 37°C, recombinant enzyme | Bifidobacterium catenulatum subsp. kashiwanohense | |
3.36 | - |
taurine | pH 7.2, 37°C, recombinant enzyme | Bifidobacterium catenulatum subsp. kashiwanohense |