Any feedback?
Literature summary for 2.2.1.6 extracted from
- Role of a highly conserved and catalytically important glutamate-49 in the Enterococcus faecalis acetolactate synthase (2013), Bull. Korean Chem. Soc., 34, 669-672.
No PubMed abstract available
Cloned(Commentary)
| Cloned (Comment) | Organism |
|---|---|
| expressed in Escherichia coli BL21(DE3) cells | Enterococcus faecalis |
| recombinant expression of wild-type and mutants enzymes in Escherichia coli strain BL21(DE3) | Enterococcus faecalis |
Protein Variants
| Protein Variants | Comment | Organism |
|---|---|---|
| E49A | site-directed mutagenesis, the mutant shows decreased activities and weakened thiamine diphosphate binding. The Km for substrate pyruvate is 22fold higher than that of the wild-type cALS. In addition, the E49A mutation also has a drastic effect on cofactor thiamine diphosphate activation. The half-saturating concentration (Kc) for thiamine diphosphate is 2000fold higher than that of wild-type cALS | Enterococcus faecalis |
| E49A | the mutation causes a 190fold reduction in affinity for thiamine diphosphate | Enterococcus faecalis |
| E49D | site-directed mutagenesis, the mutant exhibits normal substrate kinetics, with the Km for pyruvate equal to that of wild-type cALS | Enterococcus faecalis |
| E49D | the mutation causes a 150fold reduction in affinity for thiamine diphosphate | Enterococcus faecalis |
| E49Q | site-directed mutagenesis, the mutant shows decreased activities and weakened thiamine diphosphate binding, the Kc for ThDP that is 3600fold higher than that of wild-type cALS | Enterococcus faecalis |
| E49Q | the mutant causes a 170fold reduction in affinity for thiamine diphosphate shows 7% of wild type activity | Enterococcus faecalis |
| additional information | the aspartate substitution significantly affects the activation of thiamine diphosphate. The Kc for thiamine diphosphate is determined to be 280fold higher than that of wild-type cALS | Enterococcus faecalis |
KM Value [mM]
| KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
|---|---|---|---|---|---|
| additional information | - |
additional information | substrate and cofactor kinetics of wild-type and mutant enzymes, overview | Enterococcus faecalis | |
| 1.37 | - |
pyruvate | wild type enzyme, pH and temperature not specified in the publication | Enterococcus faecalis |  |
| 1.37 | - |
pyruvate | recombinant wild-type enzyme, pH and temperature not specified in the publication | Enterococcus faecalis | |
| 1.7 | - |
pyruvate | recombinant mutant E49D, pH and temperature not specified in the publication | Enterococcus faecalis | |
| 1.7 | - |
pyruvate | mutant enzyme E49D, pH and temperature not specified in the publication | Enterococcus faecalis | |
| 16.24 | - |
pyruvate | recombinant mutant E49Q, pH and temperature not specified in the publication | Enterococcus faecalis | |
| 16.24 | - |
pyruvate | mutant enzyme E49Q, pH and temperature not specified in the publication | Enterococcus faecalis | |
| 30.58 | - |
pyruvate | recombinant mutant E49A, pH and temperature not specified in the publication | Enterococcus faecalis | |
| 30.58 | - |
pyruvate | mutant enzyme E49A, pH and temperature not specified in the publication | Enterococcus faecalis | |
Metals/Ions
| Metals/Ions | Comment | Organism | Structure |
|---|---|---|---|
| Mg2+ | required | Enterococcus faecalis | |
Natural Substrates/ Products (Substrates)
| Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
|---|---|---|---|---|---|---|
| 2 pyruvate | Enterococcus faecalis | - |
2-acetolactate + CO2 | - |
? | |
Organism
| Organism | UniProt | Comment | Textmining |
|---|---|---|---|
| Enterococcus faecalis | - |
- |
- |
Purification (Commentary)
| Purification (Comment) | Organism |
|---|---|
- |
Enterococcus faecalis |
| recombinant wild-type and mutants enzymes from Escherichia coli strain BL21(DE3) | Enterococcus faecalis |
Substrates and Products (Substrate)
| Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
|---|---|---|---|---|---|---|
| 2 pyruvate | - |
Enterococcus faecalis | 2-acetolactate + CO2 | - |
? | |
Synonyms
| Synonyms | Comment | Organism |
|---|---|---|
| ALS | - |
Enterococcus faecalis |
Cofactor
| Cofactor | Comment | Organism | Structure |
|---|---|---|---|
| FAD | required | Enterococcus faecalis | |
| thiamine diphosphate | dependent on | Enterococcus faecalis | |
General Information
| General Information | Comment | Organism |
|---|---|---|
| evolution | two types of ALSs, anabolic acetohydroxyacid synthase (AHAS) and catabolic ALSs (cALS). The anabolic AHAS is primarily found in plants, fungi, and bacteria, is involved in the biosynthesis of branched-chain amino acids, and contains FAD, whereas the cALS is found only in some bacteria and is involved in the butanediol fermentation pathway. Both of the enzymes are thiamine diphosphate-dependent and require a divalent metal ion for catalytic activity. The catabolic ALS can be distinguished from anabolic AHAS by a low optimal pH of about pH 6.0, FAD-independent functionality, a genetic location within the butanediol operon, and lack of a regulatory subunit. In all of the crystal structures of ThDP-dependent enzymes determined to date, with the exception of glyoxylate carbo-ligase (GCL), a highly conerved glutamate residue is found at hydrogen-bonding distance from the N1' atom of the aminopyrimidine ring of the boundThDP and plays a key role in catalysis. In Enterococcus faecalis it is Glu49 | Enterococcus faecalis |
Use of this online version of BRENDA is free under the CC BY 4.0 license. See terms of use for full details.
Release 2023.1 (January 2023)
Legal
Curated at
Member of
