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Literature summary for 2.3.1.30 extracted from
- Single residue mutation in active site of serine acetyltransferase isoform 3 from Entamoeba histolytica assists in partial regaining of feedback inhibition by cysteine (2013), PLoS ONE, 8, e55932.
Protein Variants
| Protein Variants | Comment | Organism |
|---|---|---|
| H208S | site-directed mutagenesis, a combination of comparative modeling, multiple molecular dynamics simulations and free energy calculation studies, the mutant shows a loss of cysteine inhibition by 64% compared to wild-type isozyme SAT1 | Entamoeba histolytica |
| S208H | naturally occuring polymorphism and site-directed mutagenesis, a combination of comparative modeling, multiple molecular dynamics simulations and free energy calculation studies shows a difference in binding energies of wild-type isozyme SAT3 and of a S208H-SAT3 mutant for cysteine. The mutant shows a gain of cysteine inhibition by 36% and the IC50 of 3.5 mM, while the wild-type isozyme is almosst insensitive | Entamoeba histolytica |
Inhibitors
| Inhibitors | Comment | Organism | Structure |
|---|---|---|---|
| L-cysteine | feedback inhibition; feedback inhibition; feedback inhibition, isozyme SAT3 is almost insensitive to cysteine inhibition. A combination of comparative modeling, multiple molecular dynamics simulations and free energy calculation studies shows a difference in binding energies of wild-type isozyme SAT3 and of a S208H-SAT3 mutant for cysteine | Entamoeba histolytica |  |
| additional information | histidine 208 appears to be one of the important residues that distinguish the serine substrate from the cysteine inhibitor | Entamoeba histolytica |
KM Value [mM]
| KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
|---|---|---|---|---|---|
| additional information | - |
additional information | Michaelis-Menten kinetics, overview | Entamoeba histolytica | |
| 0.0435 | - |
L-serine | wild-type isozyme SAT1, pH 8.0, temperature not specified in the publication | Entamoeba histolytica | |
| 0.052 | - |
L-serine | wild-type isozyme SAT3, pH 8.0, temperature not specified in the publication | Entamoeba histolytica | |
| 0.0673 | - |
L-serine | wild-type isozyme SAT3, pH 8.0, temperature not specified in the publication, in presence of 10 mM L-cysteine | Entamoeba histolytica | |
| 0.0684 | - |
L-serine | isozyme SAT1 mutant H208S, pH 8.0, temperature not specified in the publication | Entamoeba histolytica | |
| 0.1855 | - |
L-serine | isozyme SAT3 mutant S208H, pH 8.0, temperature not specified in the publication | Entamoeba histolytica | |
| 0.2109 | - |
L-serine | isozyme SAT3 mutant S208HS, pH 8.0, temperature not specified in the publication, in presence of 10 mM L-cysteine | Entamoeba histolytica | |
| 0.2178 | - |
L-serine | wild-type isozyme SAT1, pH 8.0, temperature not specified in the publication, in presence of 10 mM L-cysteine | Entamoeba histolytica | |
| 0.2321 | - |
L-serine | isozyme SAT1 mutant H208S, pH 8.0, temperature not specified in the publication, in presence of 10 mM L-cysteine | Entamoeba histolytica | |
Natural Substrates/ Products (Substrates)
| Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
|---|---|---|---|---|---|---|
| acetyl-CoA + L-serine | Entamoeba histolytica | - |
CoA + O-acetyl-L-serine | - |
? | |
Organism
| Organism | UniProt | Comment | Textmining |
|---|---|---|---|
| Entamoeba histolytica | - |
- |
- |
| Entamoeba histolytica | Q401L4 | isozyme SAT3 | - |
| Entamoeba histolytica | Q401L5 | isozyme SAT2 | - |
Storage Stability
| Storage Stability | Organism |
|---|---|
| 4°C, the purified recombinant wild-type and mutant isozyme EhSAT1 proteins are stable over long storage | Entamoeba histolytica |
| 4°C, the purified recombinant wild-type and mutant isozyme EhSAT3 proteins are unstable due to protein aggregation over long storage | Entamoeba histolytica |
Substrates and Products (Substrate)
| Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
|---|---|---|---|---|---|---|
| acetyl-CoA + L-serine | - |
Entamoeba histolytica | CoA + O-acetyl-L-serine | - |
? | |
Synonyms
| Synonyms | Comment | Organism |
|---|---|---|
| SAT | - |
Entamoeba histolytica |
| SAT1 | - |
Entamoeba histolytica |
| SAT2 | - |
Entamoeba histolytica |
| SAT3 | - |
Entamoeba histolytica |
| serine acetyltransferase | - |
Entamoeba histolytica |
pH Optimum
| pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
|---|---|---|---|
| 8 | - |
assay at | Entamoeba histolytica |
IC50 Value
| IC50 Value | IC50 Value Maximum | Comment | Organism | Inhibitor | Structure |
|---|---|---|---|---|---|
| 3.5 | - |
isozyme SAT3, pH 8.0, temperature not specified in the publication | Entamoeba histolytica | L-cysteine | |
General Information
| General Information | Comment | Organism |
|---|---|---|
| evolution | the active site residues of isozymes EhSAT1 and of EhSAT3 are identical except for position 208, which is a histidine residue in isozyme EhSAT1 and a serine residue in isozyme EhSAT3 | Entamoeba histolytica |
| additional information | histidine 208 appears to be one of the important residues that distinguish the serine substrate from the cysteine inhibitor. Homology three-dimensional structure modeling of isozyme SAT3, free or in complex with cysteine or serine, using the isozyme EhSAT1 crystal structures, PDB IDs 3P47 and 3Q1X as a templates, overview | Entamoeba histolytica |
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