EC Number   |
KM Value [mM] |
KM Value Maximum [mM] |
Substrate |
Reference |
|---|
    6.1.1.5 | 0.0001 |
- |
tRNAIle |
- |
466 |
| 6.1.1.5 | 0.00028 |
- |
ATP |
- |
448 |
| 6.1.1.5 | 0.0036 |
- |
Ile |
- |
448 |
| 6.1.1.5 | 0.01 |
- |
L-isoleucine |
ATP-diphosphate exchange reaction, pH 7.9, 22°C |
651903 |
| 6.1.1.5 | 0.0001 |
- |
tRNAIle |
below, pH 7.9, 22°C |
651905 |
| 6.1.1.5 | 0.0001 |
- |
tRNAIle |
below, tRNAIle aminoacylation reaction, pH 7.9, 22°C |
651903 |
| 6.1.1.5 | -999 |
- |
more |
kinetic analysis, rapid equilibrium determinations, steady-state kinetics. The analysis strongly suggests an additional activation step, formation of a new isoleucyl-AMP before the isoleucyl-tRNA is freed from the enzyme. The removal of Ile-tRNA is possible without the formation of Ile-AMP if both isoleucine and ATP are bound to the E-Ile-tRNA complex, but this route covers only 11% of the total formation of Ile-tRNA. In addition to the Mg2+ in MgATP or Mg-diphosphate, only two tRNA-bound Mg2+ are required to explain the magnesium dependence in the best-fit mechanism. The first Mg2+ might be present in all steps before the second activation and is obligatory in the first reorganizing step and transfer step. The second Mg2+ is present only at the transfer step, whereas elsewhere it prevents the reaction, including the activation reaction |
744920 |
| 6.1.1.5 | -999 |
- |
more |
Km value of mutant enzynes with altered metal-binding sites |
452 |
| 6.1.1.5 | -999 |
- |
more |
Km value of structural analogs of adenosine 5'-triphosphate in the aminoacylation reaction |
469 |
| 6.1.1.5 | 0.118 |
- |
L-isoleucine |
mutant enzyme |
652205 |
