Cloned (Comment) | Organism |
---|---|
gene DAAT, construction of expression plasmid pENTR-AtDAT1(Col-0), pENTR-AtDAT1(A77T), pENTR-AtDAT1(T303S), and pENTR-AtDAT1(Ler), recombinant expression of C-terminally GST and N-terminally His-tagged wild-type and mutant enzymes in Escherichia coli strain BL21(DE3) RIL. The wild-type and mutant enzymes are transfected into Arabdiospsis thaliana and Nicotianan benthamiana plants via the Agrobacterium tumefaciens strain pMP90-RK GV3101 transfection system, leaf infiltration resulting in insertion lines, SALK_011686 and SALK_111981, denoted as dat1-1 and dat1-2, respectively. Histochemical staining of GUS activity in seedlings and adult plants incubated overnight at 37°C in this buffer containing 1 mM X-Gluc (5-bromo-4-chloro-3-indolyl-beta-D-glucuronic acid) and 0.5 mM K3Fe(CN)6. RT-PCR enzyme expression analysis | Arabidopsis thaliana |
Protein Variants | Comment | Organism |
---|---|---|
A77T | site-directed mutagenesis, the mutation leads to defects in AA metabolism. The mutation A77T leads to a strong decrease in the production of D-Glu and D-Ala with 2-oxoglutarate or pyruvate as substrates, respectively. Instead, the enzymatic defect of AtDAT1(A77T) is quantitatively similar to that of AtDAT1(Ler) | Arabidopsis thaliana |
A77T/T303S | naturally occuring mutation in Arabidopsis thaliana accession Ler, sequencing of the genomic locus and the cDNA of AtDAT1 from accession Ler reveals the two missense mutations leading to amino acid exchanges of the protein sequence (A77T and T303S), but solely the A77T amino acid exchange is responsible for the activity loss of AtDAT1(Ler) | Arabidopsis thaliana |
additional information | the accession M7323S displays a strongly reduced AtDAT1 transcript level. When this accession is grown on D-Met supplemented medium, defects in amino acid metabolism are observed similar to those found in accession Ler and the dat1 mutant seedlings. This defect is not just due to the reduced transcription of AtDAT1 in M7323S. Sequencing of the genomic locus and the cDNA of AtDAT1 from M7323S reveals that this gene contains a T->A mutation at genomic position +1259. This leads to a nonsense mutation at the third position of a cysteine codon (TGT) to a stop codon (TGA) at position 248 of the AA sequence (C248STOP) | Arabidopsis thaliana |
T303S | site-directed mutagenesis, the mutant enzyme with the T303S amino acid exchange AtDAT1(T303S) shows an activity comparable to wild-type AtDAT1(Col-0) | Arabidopsis thaliana |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
chloroplast | - |
Arabidopsis thaliana | 9507 | - |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
D-alanine + 2-oxoglutarate | Arabidopsis thaliana | - |
pyruvate + D-glutamate | - |
r | |
D-alanine + 2-oxoglutarate | Arabidopsis thaliana Col-0 | - |
pyruvate + D-glutamate | - |
r |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Arabidopsis thaliana | Q8L493 | and mutant accession Landsberg erecta | - |
Arabidopsis thaliana Col-0 | Q8L493 | and mutant accession Landsberg erecta | - |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
leaf | - |
Arabidopsis thaliana | - |
seedling | - |
Arabidopsis thaliana | - |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
D-alanine + 2-oxoglutarate | - |
Arabidopsis thaliana | pyruvate + D-glutamate | - |
r | |
D-alanine + 2-oxoglutarate | - |
Arabidopsis thaliana Col-0 | pyruvate + D-glutamate | - |
r | |
D-alanine + pyruvate | - |
Arabidopsis thaliana | pyruvate + D-alanine | - |
r | |
D-arginine + pyruvate | low activity | Arabidopsis thaliana | ? + D-alanine | - |
? | |
D-asparagine + pyruvate | low activity | Arabidopsis thaliana | 2-oxosuccinamate + D-alanine | - |
? | |
D-asparagine + pyruvate | low activity | Arabidopsis thaliana Col-0 | 2-oxosuccinamate + D-alanine | - |
? | |
D-aspartate + pyruvate | low activity | Arabidopsis thaliana | 2-oxosuccinate + D-alanine | - |
? | |
D-aspartate + pyruvate | low activity | Arabidopsis thaliana Col-0 | 2-oxosuccinate + D-alanine | - |
? | |
D-glutamate + pyruvate | high activity | Arabidopsis thaliana | 2-oxoglutarate + D-alanine | - |
? | |
D-glutamate + pyruvate | high activity | Arabidopsis thaliana Col-0 | 2-oxoglutarate + D-alanine | - |
? | |
D-histidine + pyruvate | low activity | Arabidopsis thaliana | 3-(1H-imidazol-4-yl)-2-oxopropanoate + D-alanine | - |
? | |
D-leucine + pyruvate | low activity | Arabidopsis thaliana | 4-methyl-2-oxopentanoate + D-alanine | - |
? | |
D-lysine + pyruvate | very low activity | Arabidopsis thaliana | ? + D-alanine | - |
? | |
D-methionine + pyruvate | D-methionine is the best and preferred substrate | Arabidopsis thaliana | 4-methylsulfanyl-2-oxobutanoate + D-alanine | - |
r | |
D-phenylalanine + pyruvate | high activity | Arabidopsis thaliana | phenylpyruvate + D-alanine | - |
? | |
D-serine + pyruvate | low activity | Arabidopsis thaliana | 3-hydroxy-2-oxopropanoate + D-alanine | - |
? | |
D-threonine + pyruvate | very low activity | Arabidopsis thaliana | 2-oxobutanoate + D-alanine | - |
? | |
D-tryptophan + pyruvate | moderate activity | Arabidopsis thaliana | 3-indole-2-oxopropanoate + D-alanine | - |
? | |
D-valine + pyruvate | low activity | Arabidopsis thaliana | 2-oxoisovalerate + D-alanine | - |
? | |
additional information | substrate specificity of enzyme AtDAT1, no or alomost no activity with D-Pro and D-Tyr, respectively | Arabidopsis thaliana | ? | - |
- |
|
additional information | substrate specificity of enzyme AtDAT1, no or alomost no activity with D-Pro and D-Tyr, respectively | Arabidopsis thaliana Col-0 | ? | - |
- |
Synonyms | Comment | Organism |
---|---|---|
AtDAT1 | - |
Arabidopsis thaliana |
D-AA transaminase | - |
Arabidopsis thaliana |
DAAT | - |
Arabidopsis thaliana |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Arabidopsis thaliana |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
8 | - |
assay at | Arabidopsis thaliana |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
pyridoxal 5'-phosphate | - |
Arabidopsis thaliana |
General Information | Comment | Organism |
---|---|---|
malfunction | the Arabidopsis accession Landsberg erecta (Ler, A77T/T303S) is defective in metabolizing D-amino acids. Atdat1 loss-of-function mutants and Arabidopsis accessions with defective AtDAT1 alleles are unable to produce the metabolites of D-Met, D-Ala, D-Glu, and L-Met. Germination of seedlings in light and dark leads to enhanced growth inhibition of atdat1 mutants on D-Met. Ethylene measurements reveal an increased D-AA stimulated ethylene production in these mutants. D-Met is preferentially malonylated instead of the ethylene precursor 1-aminocyclopropane-1-carboxylic acid (ACC). This decrease of ACC degradation should then lead to the increase of ethylene production. A reciprocal relation of malonylated methionine and ACC upon D-Met application and significantly more malonyl-methionine is observed in atdat1 mutants. Unexpectedly, the malonyl-ACC levels do not differ between mutants and wild-type. The accession M7323S displays a strongly reduced AtDAT1 transcript level due to a nonsense mutation at the third position of a cysteine codon (TGT) to a stop codon (TGA) at position 248 of the AA sequence (C248STOP) | Arabidopsis thaliana |
metabolism | AtDAT1 is the central enzyme of plant D-amino acid (D-AA) metabolism | Arabidopsis thaliana |
physiological function | AtDAT1 is a key enzyme of D-amino acid stimulated ethylene production in Arabidopsis thaliana | Arabidopsis thaliana |