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

BRENDA support

Literature summary for 2.2.1.6 extracted from

  • Belenky, I.; Steinmetz, A.; Vyazmensky, M.; Barak, Z.; Tittmann, K.; Chipman, D.M.
    Many of the functional differences between acetohydroxyacid synthase (AHAS) isozyme I and other AHASs are a result of the rapid formation and breakdown of the covalent acetolactate-thiamin diphosphate adduct in AHAS I (2012), FEBS J., 279, 1967-1979.
    View publication on PubMed

Protein Variants

Protein Variants Comment Organism
C83A about 91% of wild-type activity Escherichia coli
C83S about 126% of wild-type activity Escherichia coli
C83T about 41% of wild-type activity Escherichia coli
E60A about 48% of wild-type activity Escherichia coli
E60Q about 1% of wild-type activity Escherichia coli
L476M about 34% of wild-type activity Escherichia coli
L476M/Q480W about 47% of wild-type activity Escherichia coli
M263A about 16% of wild-type activity Escherichia coli
Q480W about 22% of wild-type activity Escherichia coli
R269Q about 0.5% of wild-type activity Escherichia coli
R289K about 11% of wild-type activity Escherichia coli
V391A about 3% of wild-type activity Escherichia coli
V477I about 8% of wild-type activity Escherichia coli

Inhibitors

Inhibitors Comment Organism Structure
sulfometuron methyl
-
Escherichia coli

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
0.33
-
pyruvate mutant C83T, pH 7.6, 37°C Escherichia coli
1.2
-
pyruvate mutant C83S, pH 7.6, 37°C Escherichia coli
1.5
-
pyruvate mutant C83A, pH 7.6, 37°C Escherichia coli
3.6
-
pyruvate mutant L476M/Q480W, pH 7.6, 37°C Escherichia coli
4.7
-
pyruvate mutant Q480W, pH 7.6, 37°C Escherichia coli
4.8
-
pyruvate wild-type, pH 7.6, 37°C Escherichia coli
8
-
pyruvate mutant V477I, pH 7.6, 37°C Escherichia coli
13
-
pyruvate mutant L476M, pH 7.6, 37°C Escherichia coli
17.9
-
pyruvate mutant V391A, pH 7.6, 37°C Escherichia coli
21
-
pyruvate mutant E60Q, pH 7.6, 37°C Escherichia coli
26
-
pyruvate mutant M263A, pH 7.6, 37°C Escherichia coli
28
-
pyruvate mutant E60A, pH 7.6, 37°C Escherichia coli
50
-
pyruvate mutant R289K, pH 7.6, 37°C Escherichia coli
124
-
pyruvate mutant R289Q, pH 7.6, 37°C Escherichia coli

Organism

Organism UniProt Comment Textmining
Escherichia coli
-
isozyme I
-

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
2 pyruvate
-
Escherichia coli 2-acetolactate + CO2
-
?
2-oxobutanoate + pyruvate
-
Escherichia coli 2-hydroxy-2-methyl-3-oxopentanoate + CO2
-
?
additional information isozyme I is not specific for 2-oxobutanoate over pyruvate as an acceptor substrate. Residues Gln480 and Met476 in AHAS I replace the Trp and Leu residues conserved in other acetohydroxyacid synthases and lead to accelerated ligation and product release steps. This difference in kinetics accounts for the unique specificity, reversibility and allosteric response of AHAS I Escherichia coli ?
-
?

Turnover Number [1/s]

Turnover Number Minimum [1/s] Turnover Number Maximum [1/s] Substrate Comment Organism Structure
2
-
pyruvate mutant C83T, pH 7.6, 37°C Escherichia coli
2
-
pyruvate mutant E60A, pH 7.6, 37°C Escherichia coli
2
-
pyruvate mutant E60Q, pH 7.6, 37°C Escherichia coli
6
-
pyruvate mutant R289Q, pH 7.6, 37°C Escherichia coli
8
-
pyruvate mutant V391A, pH 7.6, 37°C Escherichia coli
9
-
pyruvate mutant V477I, pH 7.6, 37°C Escherichia coli
15
-
pyruvate mutant Q480W, pH 7.6, 37°C Escherichia coli
20
-
pyruvate mutant C83A, pH 7.6, 37°C Escherichia coli
23
-
pyruvate mutant C83S, pH 7.6, 37°C Escherichia coli
25
-
pyruvate mutant L476M/Q480W, pH 7.6, 37°C Escherichia coli
62
-
pyruvate mutant M263A, pH 7.6, 37°C Escherichia coli
65
-
pyruvate mutant L476M, pH 7.6, 37°C Escherichia coli
71
-
pyruvate wild-type, pH 7.6, 37°C Escherichia coli
86
-
pyruvate mutant R289K, pH 7.6, 37°C Escherichia coli

Ki Value [mM]

Ki Value [mM] Ki Value maximum [mM] Inhibitor Comment Organism Structure
0.0044
-
sulfometuron methyl mutant Q480W, pH 7.6, 37°C Escherichia coli
0.041
-
sulfometuron methyl mutant L476M/Q480W, pH 7.6, 37°C Escherichia coli

kcat/KM [mM/s]

kcat/KM Value [1/mMs-1] kcat/KM Value Maximum [1/mMs-1] Substrate Comment Organism Structure
0.05
-
pyruvate mutant R289Q, pH 7.6, 37°C Escherichia coli
0.07
-
pyruvate mutant E60A, pH 7.6, 37°C Escherichia coli
0.1
-
pyruvate mutant E60Q, pH 7.6, 37°C Escherichia coli
0.46
-
pyruvate mutant V391A, pH 7.6, 37°C Escherichia coli
1.2
-
pyruvate mutant V477I, pH 7.6, 37°C Escherichia coli
1.7
-
pyruvate mutant R289K, pH 7.6, 37°C Escherichia coli
2.4
-
pyruvate mutant M263A, pH 7.6, 37°C Escherichia coli
3.3
-
pyruvate mutant Q480W, pH 7.6, 37°C Escherichia coli
5
-
pyruvate mutant L476M, pH 7.6, 37°C Escherichia coli
6.1
-
pyruvate mutant C83T, pH 7.6, 37°C Escherichia coli
6.9
-
pyruvate mutant L476M/Q480W, pH 7.6, 37°C Escherichia coli
13.5
-
pyruvate mutant C83A, pH 7.6, 37°C Escherichia coli
14.9
-
pyruvate wild-type, pH 7.6, 37°C Escherichia coli
18.8
-
pyruvate mutant C83S, pH 7.6, 37°C Escherichia coli