EC Number | Inhibitors | Comment | Organism | Structure |
---|---|---|---|---|
6.1.1.5 | chloride | 100 mM KCl causes 50% inhibition if the ionic strength is kept constant with potassium acetate. The KappM (tRNA) value is increased from 570 nm to 1370 nM when the KCl concentration is increased from 0 to 200 mM. Potassium acetate inhibits weakly, but K2SO4 inhibits stronger than KCl | Escherichia coli | |
6.1.1.5 | K+ | potassium acetate inhibits weakly, but K2SO4 inhibits stronger than KCl. KCl and potassium acetate inhibit above 50 mM concentrations when high enough K+ concentration for full activity is reached | Escherichia coli |
EC Number | KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|---|
6.1.1.5 | additional information | - |
additional information | 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 | Escherichia coli |
EC Number | Metals/Ions | Comment | Organism | Structure |
---|---|---|---|---|
6.1.1.5 | Mg2+ | required. 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 | Escherichia coli | |
6.1.1.5 | additional information | polyamines can replace part of the Mg2+ ions in the aminoacyl-tRNA synthetase reactions, spermidine can replace Mg2+ (KME3) and Mg2+ (KME42), which are involved in the forward and backward transfer reaction, while the competition with Mg2+ (KMR) is much weaker, kinetics, overview | Escherichia coli |
EC Number | Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|---|
6.1.1.5 | ATP + L-isoleucine + tRNAIle | Escherichia coli | - |
AMP + diphosphate + L-isoleucyl-tRNAIle | - |
? |
EC Number | Organism | UniProt | Comment | Textmining |
---|---|---|---|---|
6.1.1.5 | Escherichia coli | P00956 | - |
- |
EC Number | Reaction | Comment | Organism | Reaction ID |
---|---|---|---|---|
6.1.1.5 | ATP + L-isoleucine + tRNAIle = AMP + diphosphate + L-isoleucyl-tRNAIle | catalytic and kinetic mechanism analysis, reaction cycle, overview | Escherichia coli |
EC Number | Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|---|
6.1.1.5 | ATP + L-isoleucine + tRNAIle | - |
Escherichia coli | AMP + diphosphate + L-isoleucyl-tRNAIle | - |
? |
EC Number | Synonyms | Comment | Organism |
---|---|---|---|
6.1.1.5 | IleRS | - |
Escherichia coli |
6.1.1.5 | Isoleucyl-tRNA synthetase | - |
Escherichia coli |
EC Number | Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|---|
6.1.1.5 | 30 | - |
assay at | Escherichia coli |
EC Number | pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|---|
6.1.1.5 | 7.4 | - |
assay at | Escherichia coli |
EC Number | Cofactor | Comment | Organism | Structure |
---|---|---|---|---|
6.1.1.5 | ATP | - |
Escherichia coli |
EC Number | General Information | Comment | Organism |
---|---|---|---|
6.1.1.5 | additional information | the simultaneous presence of Ile-tRNA and Ile-AMP can cause additional possibilities to proofreading mechanisms of the enzyme, existence of 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 | Escherichia coli |