Any feedback?
Please rate this page
(literature.php)
(0/150)

BRENDA support

Literature summary for 6.1.1.5 extracted from

  • Dulic, M.; Cvetesic, N.; Perona, J.J.; Gruic-Sovulj, I.
    Partitioning of tRNA-dependent editing between pre- and post-transfer pathways in class I aminoacyl-tRNA synthetases (2010), J. Biol. Chem., 285, 23799-23809.
    View publication on PubMedView publication on EuropePMC
Search for more literature for 6.1.1.5

Cloned(Commentary)

Cloned (Comment) Organism
overexpression of His-tagged IleRS in Escherichia coli strain BL21 (DE3) Escherichia coli

Protein Variants

Protein Variants Comment Organism
D342A site-directed mutagenesis, the IleRS CP1 domain mutant is unable to deacylate misacylated tRNA even at high enzyme concentrations Escherichia coli
T243R site-directed mutagenesis, the mutant retains tRNA-independent editing at a level identical to the WT enzyme and shows increased ATP hydrolysis compared to the wild-type enzyme Escherichia coli
T243R/D342A site-directed mutagenesis, the IleRS CP1 domain mutant is unable to deacylate misacylated tRNA even at high enzyme concentrations Escherichia coli

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
additional information
-
 additional information steady-state parameters for tRNA-independent pre-transfer editing by IleRS and its mutants determined by varying concentrations of noncognate valine, overview. Kinetic method to distinguish among three models for pre-transfer editing by IleRS, overview Escherichia coli
0.6
-
 ATP pH 7.5, 37°C, mutant T243R/D342A, in presence of tRNA Escherichia coli
0.7
-
 ATP pH 7.5, 37°C, mutant T234R, in presence of tRNA Escherichia coli
2.4
-
 ATP pH 7.5, 37°C, mutant D342A, in presence of tRNA Escherichia coli
4.4
-
 ATP pH 7.5, 37°C, wild-type IleRS, in presence of tRNA Escherichia coli

Metals/Ions

Metals/Ions Comment Organism Structure
Mg2+ assay at Escherichia coli

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
ATP + L-isoleucine + tRNAIle Escherichia coli
-
 AMP + diphosphate + L-isoleucyl-tRNAIle
-
 ?

Organism

Organism UniProt Comment Textmining
Escherichia coli
-
-
-

Purification (Commentary)

Purification (Comment) Organism
recombinant His-tagged IleRS from Escherichia coli strain BL21 (DE3) by nickel affinity chromatography Escherichia coli

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg] Specific Activity Maximum [µmol/min/mg] Comment Organism
additional information
-
 rate constants for hydrolysis and transfer of a noncognate intermediate are roughly equal in IleRS Escherichia coli

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
ATP + L-isoleucine + tRNAIle
-
 Escherichia coli AMP + diphosphate + L-isoleucyl-tRNAIle
-
 ?

Synonyms

Synonyms Comment Organism
IleRS
-
 Escherichia coli
Isoleucyl-tRNA synthetase
-
 Escherichia coli
More the enzyme is a class I aminoacyl-tRNA synthetase Escherichia coli

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
37
-
 assay at, aminoacylation and deacylation reactions Escherichia coli

Turnover Number [1/s]

Turnover Number Minimum [1/s] Turnover Number Maximum [1/s] Substrate Comment Organism Structure
0.29
-
 ATP pH 7.5, 37°C, mutant T243R/D342A, in presence of tRNA Escherichia coli
0.48
-
 ATP pH 7.5, 37°C, mutant D342A, in presence of tRNA Escherichia coli
1.04
-
 ATP pH 7.5, 37°C, mutant T234R, in presence of tRNA Escherichia coli
1.56
-
 ATP pH 7.5, 37°C, wild-type IleRS, in presence of tRNA Escherichia coli

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
7.5
-
 assay at, aminoacylation and deacylation reactions Escherichia coli

Cofactor

Cofactor Comment Organism Structure
ATP
-
 Escherichia coli

General Information

General Information Comment Organism
physiological function hydrolytic editing activities are present in aminoacyl-tRNA synthetases possessing reduced amino acid discrimination in the synthetic reactions. Post-transfer hydrolysis of misacylated tRNA in class I editing enzymes, e.g. IleRS, occurs in a spatially separate domain inserted into the catalytic Rossmann fold. tRNA-dependent hydrolysis of noncognate valyl-adenylate by IleRS is largely insensitive to mutations in the editing domain of the enzyme and that noncatalytic hydrolysis after release is too slow to account for the observed rate of clearing. Pre-transfer editing in IleRS is an enzyme-catalyzed activity residing in the synthetic active site. Balance between pretransfer and post-transfer editing pathways is controlled by kinetic partitioning of the noncognate aminoacyl-adenylate, overview. In IleRS both pre- and post-transfer editing are important Escherichia coli

kcat/KM [mM/s]

kcat/KM Value [1/mMs-1] kcat/KM Value Maximum [1/mMs-1] Substrate Comment Organism Structure
0.2
-
 ATP pH 7.5, 37°C, mutant D342A, in presence of tRNA Escherichia coli
0.35
-
 ATP pH 7.5, 37°C, wild-type IleRS, in presence of tRNA Escherichia coli
0.48
-
 ATP pH 7.5, 37°C, mutant T243R/D342A, in presence of tRNA Escherichia coli
1.49
-
 ATP pH 7.5, 37°C, mutant T234R, in presence of tRNA Escherichia coli