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

BRENDA support

Literature summary for 6.1.1.9 extracted from

  • Hountondji, C.; Lazennec, C.; Beauvallet, C.; Dessen, P.; Pernollet, J.C.; Plateau, P.; Blanquet, S.
    Crucial role of conserved lysine 277 in the fidelity of tRNA aminoacylation by Escherichia coli valyl-tRNA synthetase (2002), Biochemistry, 41, 14856-14865.
    View publication on PubMed

Cloned(Commentary)

Cloned (Comment) Organism
gene valS, expression of His-tagged wild-type and mutant enzymes in strain JM101Tr Escherichia coli

Protein Variants

Protein Variants Comment Organism
K277A site-directed mutagenesis, mutant exhibits a reduced posttransfer editing activity compared to the wild-type, also the specificiy of the editing reaction is modulated, the mutant hydrolyzes the correctly formed Val-tRNAVal, increased sensitivity to Mg2+, high concentrations inactivate Escherichia coli

Inhibitors

Inhibitors Comment Organism Structure
additional information incorporation of 2.1 mol L-valine per mol of enzyme leads to inactivation Escherichia coli

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
0.00008
-
tRNAVal aminoacylation reaction with L-valine, wild-type enzyme, pH 7.5, 25°C Escherichia coli
0.0001
-
tRNAVal aminoacylation reaction with L-valine, His-tagged wild-type enzyme, pH 7.5, 25°C Escherichia coli
0.0001
-
tRNAVal aminoacylation reaction with L-valine, K277A mutant enzyme, pH 7.5, 25°C Escherichia coli
0.00026
-
tRNAVal aminoacylation reaction with L-valine, His-tagged K277A mutant enzyme, pH 7.5, 25°C Escherichia coli
0.0019
-
L-valine aminoacylation reaction, His-tagged K277A mutant enzyme, pH 7.5, 25°C Escherichia coli
0.047
-
L-valine aminoacylation reaction, His-tagged wild-type enzyme, pH 7.5, 25°C Escherichia coli
0.062
-
L-valine ATP-diphosphate exchange reaction, native wild-type enzyme, pH 7.5, 25°C Escherichia coli
0.07
-
L-valine ATP-diphosphate exchange reaction, His-tagged wild-type enzyme, pH 7.5, 25°C Escherichia coli
0.072
-
L-valine ATP-diphosphate exchange reaction, His-tagged K277A mutant enzyme, pH 7.5, 25°C Escherichia coli
0.11
-
ATP ATP-diphosphate exchange reaction, His-tagged wild-type and mutant enzymes, pH 7.5, 25°C Escherichia coli
0.3
-
L-threonine ATP-diphosphate exchange reaction, native wild-type enzyme, pH 7.5, 25°C Escherichia coli

Metals/Ions

Metals/Ions Comment Organism Structure
Mg2+ required, high concentrations partly inactivate the mutant 277A Escherichia coli

Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
ATP + L-valine + tRNAVal Escherichia coli
-
AMP + diphosphate + L-valyl-tRNAVal
-
ir

Organism

Organism UniProt Comment Textmining
Escherichia coli
-
-
-

Purification (Commentary)

Purification (Comment) Organism
recombinantly expressed His-tagged wild-type and mutant enzymes Escherichia coli

Reaction

Reaction Comment Organism Reaction ID
ATP + L-valine + tRNAVal = AMP + diphosphate + L-valyl-tRNAVal Lys593 and Lys554 are in the active site binding valine or threonine, part of the 554KMSKS558 consensus sequence, mechanism, determination of diverse amino acid residues of the enzyme molecule involved in substrate binding, Lys277 plays a crucial role in the fidelity of tRNA aminoacylation by the enzyme, nucleophilic attack of misacylated tRNA in the diting site of the enzyme Escherichia coli

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
ATP + L-threonine + tRNAVal noncognate isosteric substrate, low activity, posttransfer editing occurs Escherichia coli AMP + diphosphate + L-threonyl-tRNAVal
-
ir
ATP + L-valine + tRNAVal
-
Escherichia coli AMP + diphosphate + L-valyl-tRNAVal
-
ir
ATP + L-valine + tRNAVal two-step reaction, covalent valylation of the enzyme Escherichia coli AMP + diphosphate + L-valyl-tRNAVal
-
ir
additional information the enzyme also performs the ATP-diphosphate exchange reaction, labeling of the enzyme by methionyladenylate, determination of lysine residues involved in binding Escherichia coli ?
-
?

Synonyms

Synonyms Comment Organism
G7a
-
Escherichia coli
Synthetase, valyl-transfer ribonucleate
-
Escherichia coli
Valine transfer ribonucleate ligase
-
Escherichia coli
Valine translase
-
Escherichia coli
Valine--tRNA ligase
-
Escherichia coli
ValRS
-
Escherichia coli
Valyl transfer ribonucleic acid synthetase
-
Escherichia coli
Valyl-transfer ribonucleate synthetase
-
Escherichia coli
Valyl-transfer RNA synthetase
-
Escherichia coli
Valyl-tRNA ligase
-
Escherichia coli
Valyl-tRNA synthetase
-
Escherichia coli

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
25
-
assay at Escherichia coli

Turnover Number [1/s]

Turnover Number Minimum [1/s] Turnover Number Maximum [1/s] Substrate Comment Organism Structure
additional information
-
additional information rate of hydrolysis of Thr-tRNAVal and Val-tRNAVal by wild-type and mutant enzyme, incorporation of amino acids valine and threonine into the enzyme Escherichia coli
0.064
-
L-valine aminoacylation reaction, His-tagged K277A mutant enzyme, pH 7.5, 25°C Escherichia coli
1.5
-
tRNAVal aminoacylation reaction with L-valine, K277A mutant enzyme, pH 7.5, 25°C Escherichia coli
1.5
-
L-valine aminoacylation reaction, His-tagged wild-type enzyme, pH 7.5, 25°C Escherichia coli
1.7
-
tRNAVal aminoacylation reaction with L-valine, wild-type enzyme, pH 7.5, 25°C Escherichia coli
50
-
ATP ATP-diphosphate exchange reaction, His-tagged wild-type enzyme, pH 7.5, 25°C Escherichia coli
50
-
tRNAVal ATP-diphosphate exchange reaction, K277A mutant enzyme, pH 7.5, 25°C Escherichia coli
51
-
tRNAVal ATP-diphosphate exchange reaction, wild-type enzyme, pH 7.5, 25°C Escherichia coli
57
-
ATP ATP-diphosphate exchange reaction, His-tagged K277A mutant enzyme, pH 7.5, 25°C Escherichia coli

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
7.5
-
assay at Escherichia coli

Cofactor

Cofactor Comment Organism Structure
ATP
-
Escherichia coli