Cloned (Comment) | Organism |
---|---|
expressed in Escherichia coli | Escherichia coli |
Crystallization (Comment) | Organism |
---|---|
the crystal triple mutant I33Q/Y214Q/R280Y is determined to relate the observed changes in reaction kinetics to the changes in active-site structure | Escherichia coli |
Protein Variants | Comment | Organism |
---|---|---|
I33Q/Y214Q/R280Y | substitution of three active-site residues in Escherichia coli L-aspartateartate aminotransferase highly reduces kcat for transamination reaction. Ratio of L-cysteine sulfinate desulfinase to transaminase activity is increased by 100000fold in mutant. kcat for desulfination of L-cysteine sulfinate increases to 0.5/sec (from 0.05/sec in wild-type enzyme). kcat for beta-decarboxylation of L-aspartateartate increases from below 0.0001/sec to 0.07/sec | Escherichia coli |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
3.1 | - |
L-aspartate | pH 7.5, 25°C, mutant I33Q/Y214Q/R280Y | Escherichia coli | |
4 | - |
L-aspartate | pH 7.5, 25°C, wild-type | Escherichia coli | |
5.2 | - |
L-glutamate | pH 7.5, 25°C, mutant I33Q/Y214Q/R280Y | Escherichia coli | |
37 | - |
L-glutamate | pH 7.5, 25°C, wild-type | Escherichia coli |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | P00509 | - |
- |
Purification (Comment) | Organism |
---|---|
EcAspAT is purified by anion exchange chromatography in a Fractogel EMD DEAE 650-S column, pooled fractions are dialyzed against 20 mM sodium phosphate, pH 7.5, and loaded onto a ceramic hydroxyapatite column | Escherichia coli |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-aspartate + 2-oxoglutarate | - |
Escherichia coli | oxaloacetate + L-glutamate | - |
r |
Synonyms | Comment | Organism |
---|---|---|
EcAspAT | wild-type enzyme shows weak desulfination activity and decarboxylation activity | Escherichia coli |
L-aspartateartate aminotransferase | - |
Escherichia coli |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
25 | - |
assay at | Escherichia coli |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.03 | - |
L-glutamate | pH 7.5, 25°C, mutant I33Q/Y214Q/R280Y | Escherichia coli | |
0.13 | - |
L-aspartate | pH 7.5, 25°C, mutant I33Q/Y214Q/R280Y | Escherichia coli | |
530 | - |
L-aspartate | pH 7.5, 25°C, wild-type | Escherichia coli | |
670 | - |
L-glutamate | pH 7.5, 25°C, wild-type | Escherichia coli |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.5 | - |
assay at | Escherichia coli |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
pyridoxal 5'-phosphate | - |
Escherichia coli | |
pyridoxamine 5'-phosphate | - |
Escherichia coli |
kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.006 | - |
L-glutamate | pH 7.5, 25°C, mutant I33Q/Y214Q/R280Y | Escherichia coli | |
0.042 | - |
L-aspartate | pH 7.5, 25°C, mutant I33Q/Y214Q/R280Y | Escherichia coli | |
18 | - |
L-glutamate | pH 7.5, 25°C, wild-type | Escherichia coli | |
133 | - |
L-aspartate | pH 7.5, 25°C, wild-type | Escherichia coli |