Cloned (Comment) | Organism |
---|---|
gene AtGSA1, recombinant expression of His6-tagged enzyme lacking the N-terminal plastid-targeting sequences in Escherichia coli strain BL21(DE3) | Arabidopsis thaliana |
Crystallization (Comment) | Organism |
---|---|
purified recombinant detagged enzyme, sitting drop vapour diffusion method, mixing of 0.001 ml of 8 mg/ml protein in 20 mM Tris-HCl, pH 7.5, and 200 mM NaCl, with 0.001 ml of reservoir solution containing 0.15 M potassium bromide, and 30% w/v PEG 2000 MME, and equilibration against 0.2 ml reservoir solution, X-ray diffraction structure determination and analysis at 1.25 A resolution | Arabidopsis thaliana |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
chloroplast | the enzyme has an N-terminal plastid-targeting sequence | Arabidopsis thaliana | 9507 | - |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-glutamate 1-semialdehyde | Arabidopsis thaliana | - |
5-aminolevulinate | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Arabidopsis thaliana | P42799 | - |
- |
Purification (Comment) | Organism |
---|---|
recombinant His6-tagged enzyme from Escherichia coli strain BL21(DE3) by nickel affinity chromatography, removal of the His-tag through TEV protease, followed by gel filtration, and ultrafiltration | Arabidopsis thaliana |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-glutamate 1-semialdehyde | - |
Arabidopsis thaliana | 5-aminolevulinate | - |
? | |
additional information | enzyme GSAM catalyzes the transamination of GSA substrate to form 5-aminolevulinate by an unusual intramolecular exchange of amino and oxo groups via the intermediate 4,5-diaminovalerate (DAVA). The reaction starts with imine formation between pyridoxamine 5'-phosphate and the aldehyde of GSA. During the first half of the reaction pyridoxamine 5'-phosphate is converted to pyridoxal 5'-phosphate, while pyridoxamine 5'-phosphate is regenerated in the second half of the reaction upon 5-aminolevulinate formation | Arabidopsis thaliana | ? | - |
? |
Subunits | Comment | Organism |
---|---|---|
dimer | enzyme AtGSA1 forms an asymmetric dimer and displays asymmetry in cofactor binding as well as in the gating-loop orientation | Arabidopsis thaliana |
More | the overall structure of AtGSA1 consists of three sequentially arranged domains: the N-terminal domain (Val1-Asp63, mature protein) comprises one alpha-helix and a three-stranded antiparallel beta-sheet, the pyridoxamine 5'-phosphate/pyridoxal 5'-phosphate-binding domain (Tyr64-Gly328), which is also the catalytic domain, contains a central seven-stranded beta-sheet with one antiparallel and six parallel beta-strands, and the C-terminal domain (Thr329-Ile434) is composed of a three-stranded antiparallel beta-sheet with four helices covering the outer surface. Asymmetry of AtGSA1 in the gating-loop conformation, overview | Arabidopsis thaliana |
Synonyms | Comment | Organism |
---|---|---|
AtGSA1 | - |
Arabidopsis thaliana |
Glutamate-1-semialdehyde aminotransferase | - |
Arabidopsis thaliana |
glutamate-1-semialdehyde-2,1-aminomutase | - |
Arabidopsis thaliana |
GSA-AT | - |
Arabidopsis thaliana |
GSA1 | - |
Arabidopsis thaliana |
GSAM | - |
Arabidopsis thaliana |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
additional information | during the first half of the reaction pyridoxamine 5'-phosphate is converted to pyridoxal 5'-phosphate, while pyridoxamine 5'-phosphate is regenerated in the second half of the reaction upon 5-aminolevulinate formation | Arabidopsis thaliana | |
pyridoxal 5'-phosphate | a pyridoxamine 5'-phosphate (PMP)/pyridoxal 5'-phosphate (PLP)-dependent enzyme, binding structure, overview | Arabidopsis thaliana | |
pyridoxamine 5'-phosphate | a pyridoxamine 5'-phosphate (PMP)/pyridoxal 5'-phosphate (PLP)-dependent enzyme, binding structure, overview | Arabidopsis thaliana |
General Information | Comment | Organism |
---|---|---|
additional information | structure-function analysis., overview. Enzyme AtGSA1 forms an asymmetric dimer and displays asymmetry in cofactor binding as well as in the gating-loop orientation. The mobility of residues Gly163, Ser164 and Gly165 is important for reorientation of the gating loop. The asymmetry of the AtGSA1 structure supports the previously proposed negative cooperativity between monomers of GSAM | Arabidopsis thaliana |