Cloned (Comment) | Organism |
---|---|
gene pop2, expression of N-termminally His6-tagged GABA-T POP2 in Escherichia coli strain BL-21(DE3) Rosetta (pLysS) | Arabidopsis thaliana |
transient expression of GABA-T in Nicotiana tabacum BY-2 cells. C-terminal myc-tagged GABA-T co-localizes with coexpressed mitochondrial betaATPase-CAT in BY-2 cells | Arabidopsis thaliana |
Protein Variants | Comment | Organism |
---|---|---|
additional information | a truncated AtGABA-T cDNA lacking the putative N-terminal targeting pre-sequence is co-expressed with the molecular chaperones GroES/EL in Escherichia coli, substrate specificity and kinetic studies reveal that the recombinant enzyme utilizes only GABA as the amino donor in the production of succinate semialdehyde | Arabidopsis thaliana |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
beta-Alanine | - |
Arabidopsis thaliana | |
glycine | - |
Arabidopsis thaliana | |
ornithine | - |
Arabidopsis thaliana | |
vigabatrin | - |
Arabidopsis thaliana |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | Michaelis-Menten kinetic analysis, overview | Arabidopsis thaliana | |
0.014 | - |
succinate semialdehyde | reverse reaction with L-alanine, pH 9.0, 30°C | Arabidopsis thaliana | |
0.11 | - |
glyoxylate | forward reaction with 4-aminobutanoate, pH 9.0, 30°C | Arabidopsis thaliana | |
0.14 | - |
pyruvate | forward reaction with 4-aminobutanoate, pH 9.0, 30°C | Arabidopsis thaliana | |
0.14 | - |
glyoxylate | reverse reaction with L-alanine, pH 9.0, 30°C | Arabidopsis thaliana | |
0.18 | - |
4-aminobutanoate | forward reaction with glyoxylate, pH 9.0, 30°C | Arabidopsis thaliana | |
0.34 | - |
4-aminobutanoate | forward reaction with pyruvate, pH 9.0, 30°C | Arabidopsis thaliana | |
2.2 | - |
L-alanine | reverse reaction with glyoxylate, pH 9.0, 30°C | Arabidopsis thaliana | |
2.4 | - |
L-alanine | reverse reaction with succinate semialdehyde, pH 9.0, 30°C | Arabidopsis thaliana |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
mitochondrion | - |
Arabidopsis thaliana | 5739 | - |
additional information | subcellular localization analysis, overview | Arabidopsis thaliana | - |
- |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
53400 | - |
x * 57500, recombinant full-length GABA-T, SDS-PAGE, x * 53400, recombinant truncated GABA-T, SDS-PAGE | Arabidopsis thaliana |
57500 | - |
x * 57500, recombinant full-length GABA-T, SDS-PAGE, x * 53400, recombinant truncated GABA-T, SDS-PAGE | Arabidopsis thaliana |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
4-aminobutanoate + glyoxylate | Arabidopsis thaliana | - |
succinate semialdehyde + glycine | - |
ir | |
4-aminobutanoate + glyoxylate | Arabidopsis thaliana Wassilewskija | - |
succinate semialdehyde + glycine | - |
ir | |
4-aminobutanoate + glyoxylate | Arabidopsis thaliana Col-0 | - |
succinate semialdehyde + glycine | - |
ir | |
4-aminobutanoate + pyruvate | Arabidopsis thaliana | - |
succinate semialdehyde + L-alanine | - |
r |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Arabidopsis thaliana | Q94CE5 | gene GABAT1-1 (Salk_007661) and knockout line of ecotype Columbia | - |
Arabidopsis thaliana | Q94CE5 | POP2; gene pop2, POP2-3 (CS6387) and knockout line of ecotypes Wassilewskija | - |
Arabidopsis thaliana Col-0 | Q94CE5 | gene GABAT1-1 (Salk_007661) and knockout line of ecotype Columbia | - |
Arabidopsis thaliana Wassilewskija | Q94CE5 | POP2; gene pop2, POP2-3 (CS6387) and knockout line of ecotypes Wassilewskija | - |
Purification (Comment) | Organism |
---|---|
recombinant His6-tagged GABA-T POP2 from Escherichia coli strain BL-21(DE3) Rosetta (pLysS) by nickel affinity chromatography | Arabidopsis thaliana |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
seedling | - |
Arabidopsis thaliana | - |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
additional information | - |
native GABA-T activity in cell-free extracts of Arabidopsis thaliana ecotype Columbia and corresponding knockout mutant, overview | Arabidopsis thaliana |
additional information | - |
native GABA-T activity in cell-free extracts of Arabidopsis thaliana ecotype Wassilewskija and corresponding knockout mutant, overview | Arabidopsis thaliana |
0.0004 | - |
crude enzyme extract, substrate pyruvate, pH 9.0, 30°C | Arabidopsis thaliana |
3.53 | - |
purified recombinant full-length enzyme, substrate pyruvate, pH 9.0, 30°C | Arabidopsis thaliana |
7.54 | - |
purified recombinant truncated enzyme, substrate pyruvate, pH 9.0, 30°C | Arabidopsis thaliana |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
4-aminobutanoate + glyoxylate | - |
Arabidopsis thaliana | succinate semialdehyde + glycine | - |
ir | |
4-aminobutanoate + glyoxylate | the glyoxylate-dependent reaction is not reversible, although glyoxylate can also be used in conjunction with alanine as a substrate in the reverse reaction | Arabidopsis thaliana | succinate semialdehyde + glycine | - |
ir | |
4-aminobutanoate + glyoxylate | - |
Arabidopsis thaliana Wassilewskija | succinate semialdehyde + glycine | - |
ir | |
4-aminobutanoate + glyoxylate | - |
Arabidopsis thaliana Col-0 | succinate semialdehyde + glycine | - |
ir | |
4-aminobutanoate + pyruvate | - |
Arabidopsis thaliana | succinate semialdehyde + L-alanine | - |
r | |
4-aminobutanoate + pyruvate | the pyruvate-dependent GABA-T reaction is reversible | Arabidopsis thaliana | succinate semialdehyde + L-alanine | - |
r | |
glyoxylate + L-alanine | - |
Arabidopsis thaliana | ? | - |
? | |
additional information | GABA-T catalyses the breakdown of GABA to succinic semialdehyde. The enzyme shows both pyruvate- and glyoxylate-dependent activities, but no activity with 2-oxoglutarate. The substrate specificity at pH 9 reveals that the enzyme utilizes glyoxylate, as well as pyruvate, as amino acceptors in the forward reaction, and GABA, but not beta-alanine, ornithine, acetylornithine, serine, glycine, asparagine, glutamine, glutamate, valine, leucine, isoleucine, methionine, phenylalanine, histidine, lysine, arginine, aspartate, threonine, tyrosine, tryptophan, proline, or cysteine as amino donors | Arabidopsis thaliana | ? | - |
? | |
additional information | GABA-T catalyses the breakdown of GABA to succinic semialdehyde. The enzyme shows both pyruvate- and glyoxylate-dependent activities, but no activity with 2-oxoglutarate. The substrate specificity at pH 9 reveals that the enzyme utilizes glyoxylate, as well as pyruvate, as amino acceptors in the forward reaction, and GABA, but not beta-alanine, ornithine, acetylornithine, serine, glycine, asparagine, glutamine, glutamate, valine, leucine, isoleucine, methionine, phenylalanine, histidine, lysine, arginine, aspartate, threonine, tyrosine, tryptophan, proline, or cysteine as amino donors | Arabidopsis thaliana Wassilewskija | ? | - |
? | |
additional information | GABA-T catalyses the breakdown of GABA to succinic semialdehyde. The enzyme shows both pyruvate- and glyoxylate-dependent activities, but no activity with 2-oxoglutarate. The substrate specificity at pH 9 reveals that the enzyme utilizes glyoxylate, as well as pyruvate, as amino acceptors in the forward reaction, and GABA, but not beta-alanine, ornithine, acetylornithine, serine, glycine, asparagine, glutamine, glutamate, valine, leucine, isoleucine, methionine, phenylalanine, histidine, lysine, arginine, aspartate, threonine, tyrosine, tryptophan, proline, or cysteine as amino donors | Arabidopsis thaliana Col-0 | ? | - |
? |
Subunits | Comment | Organism |
---|---|---|
? | x * 57500, recombinant full-length GABA-T, SDS-PAGE, x * 53400, recombinant truncated GABA-T, SDS-PAGE | Arabidopsis thaliana |
Synonyms | Comment | Organism |
---|---|---|
GABA-T | - |
Arabidopsis thaliana |
gamma-aminobutyrate transaminase | - |
Arabidopsis thaliana |
Pop2 | - |
Arabidopsis thaliana |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
30 | - |
assay at | Arabidopsis thaliana |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
6.9 | - |
4-aminobutanoate | forward reaction with glyoxylate, pH 9.0, 30°C | Arabidopsis thaliana | |
9.7 | - |
glyoxylate | forward reaction with 4-aminobutanoate, pH 9.0, 30°C | Arabidopsis thaliana | |
10.6 | - |
pyruvate | forward reaction with 4-aminobutanoate, pH 9.0, 30°C | Arabidopsis thaliana | |
10.6 | - |
4-aminobutanoate | forward reaction with pyruvate, pH 9.0, 30°C | Arabidopsis thaliana | |
10.8 | - |
succinate semialdehyde | reverse reaction with L-alanine, pH 9.0, 30°C | Arabidopsis thaliana | |
12.1 | - |
glyoxylate | reverse reaction with L-alanine, pH 9.0, 30°C | Arabidopsis thaliana | |
14.1 | - |
L-alanine | reverse reaction with glyoxylate, pH 9.0, 30°C | Arabidopsis thaliana | |
15.4 | - |
L-alanine | reverse reaction with succinate semialdehyde, pH 9.0, 30°C | Arabidopsis thaliana |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
9 | - |
pyruvate-dependent forward reaction | Arabidopsis thaliana |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
8 | 10.5 | pyruvate-dependent forward reaction | Arabidopsis thaliana |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
pyridoxal 5'-phosphate | - |
Arabidopsis thaliana |
Ki Value [mM] | Ki Value maximum [mM] | Inhibitor | Comment | Organism | Structure |
---|---|---|---|---|---|
0.46 | - |
ornithine | forward reaction with 4-aminobutanoate and pyruvate, pH 9.0, 30°C | Arabidopsis thaliana | |
0.55 | - |
beta-Alanine | forward reaction with 4-aminobutanoate and pyruvate, pH 9.0, 30°C | Arabidopsis thaliana | |
0.62 | - |
vigabatrin | forward reaction with 4-aminobutanoate and pyruvate, pH 9.0, 30°C | Arabidopsis thaliana | |
3.7 | - |
glycine | forward reaction with 4-aminobutanoate and pyruvate, pH 9.0, 30°C | Arabidopsis thaliana |
kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
6.4 | - |
L-alanine | reverse reaction with succinate semialdehyde, pH 9.0, 30°C | Arabidopsis thaliana | |
6.5 | - |
L-alanine | reverse reaction with glyoxylate, pH 9.0, 30°C | Arabidopsis thaliana | |
31 | - |
4-aminobutanoate | forward reaction with pyruvate, pH 9.0, 30°C | Arabidopsis thaliana | |
39 | - |
4-aminobutanoate | forward reaction with glyoxylate, pH 9.0, 30°C | Arabidopsis thaliana | |
76 | - |
pyruvate | forward reaction with 4-aminobutanoate, pH 9.0, 30°C | Arabidopsis thaliana | |
86 | - |
glyoxylate | reverse reaction with L-alanine, pH 9.0, 30°C | Arabidopsis thaliana | |
88 | - |
glyoxylate | forward reaction with 4-aminobutanoate, pH 9.0, 30°C | Arabidopsis thaliana | |
770 | - |
succinate semialdehyde | reverse reaction with L-alanine, pH 9.0, 30°C | Arabidopsis thaliana |