2.2.1.6: acetolactate synthase
This is an abbreviated version!
For detailed information about acetolactate synthase, go to the full flat file.
Word Map on EC 2.2.1.6
-
2.2.1.6
-
herbicide
-
weed
-
sulfonylurea
-
als-inhibiting
-
branched-chain
-
imidazolinone
-
biotype
-
cross-resistance
-
herbicide-resistant
-
imazethapyr
-
chlorsulfuron
-
triazolopyrimidine
-
4.1.3.18
-
als-inhibitors
-
glyphosate
-
target-site
-
amaranthus
-
imazamox
-
acetoin
-
sulfometuron
-
2,3-butanediol
-
echinochloa
-
protoporphyrinogen
-
broadleaf
-
2-ketobutyrate
-
non-target-site
-
whole-plant
-
nicosulfuron
-
accase
-
hybridus
-
rigidum
-
waterhemp
-
mesotrione
-
postemergence
-
crus-galli
-
safener
-
5-enolpyruvylshikimate-3-phosphate
-
ilvced
-
alpha-ketobutyrate
-
brewing
-
rudis
-
dicamba
-
synthesis
-
agriculture
-
molecular biology
-
glufosinate
-
thdp-dependent
-
palmeri
-
tuberculatus
-
analysis
-
alopecurus
-
isomeroreductase
-
pharmacology
-
herbicide-binding
-
drug development
-
glyphosate-resistant
-
kochia
-
biotechnology
- 2.2.1.6
-
herbicide
-
weed
- sulfonylurea
-
als-inhibiting
-
branched-chain
- imidazolinone
-
biotype
-
cross-resistance
-
herbicide-resistant
- imazethapyr
- chlorsulfuron
- triazolopyrimidine
-
4.1.3.18
-
als-inhibitors
- glyphosate
-
target-site
- amaranthus
- imazamox
- acetoin
- sulfometuron
- 2,3-butanediol
- echinochloa
- protoporphyrinogen
-
broadleaf
- 2-ketobutyrate
-
non-target-site
-
whole-plant
- nicosulfuron
- accase
- hybridus
- rigidum
-
waterhemp
- mesotrione
-
postemergence
- crus-galli
-
safener
- 5-enolpyruvylshikimate-3-phosphate
-
ilvced
- alpha-ketobutyrate
- brewing
- rudis
- dicamba
- synthesis
- agriculture
- molecular biology
- glufosinate
-
thdp-dependent
- palmeri
- tuberculatus
- analysis
-
alopecurus
-
isomeroreductase
- pharmacology
-
herbicide-binding
- drug development
-
glyphosate-resistant
- kochia
- biotechnology
Reaction
2 pyruvate
=
Synonyms
aceto-hydroxy acid synthase, acetohydroxy acid synthase, acetohydroxy acid synthase I, acetohydroxy acid synthetase, acetohydroxyacid synthase, acetolactate pyruvate-lyase (carboxylating), acetolactate synthase, acetolactate synthetase, acetolactate-synthase, acetolactic synthetase, AHAS, AHAS II, AHAS1, AHAS2, AHAS3, AHASL, AHASS, alpha-acetohydroxy acid synthetase, alpha-acetohydroxyacid synthase, alpha-acetolactate synthase, alpha-acetolactate synthetase, alpha-ALS, ALS, ALS1, ALS1R, ALS2, AlsS, CalS, catabolic acetolactate synthase, EC 4.1.3.18, GST-mALS, GST-wALS, Ilv2, Ilv6, ilvB, ilvB1, ilvB2, ilvG, IlvN, ilvX, Moilv2, Moilv6, More, PF0935, sll1981, synthase, acetolactate, TM_0548, TM_0549, TTHA1213
ECTree
2.2.1.6 acetolactate synthaseAdvanced search results
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results (Substrates Products
Substrates Products on EC 2.2.1.6 - acetolactate synthase
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SUBSTRATE 
PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
(Substrate)
LITERATURE
(Substrate)
(Substrate)
COMMENTARY
(Product)
(Product)
LITERATURE
(Product)
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
r=reversible
ir=irreversible
?=not specified
1-(2-bromo-5-hydroxyphenoxy)propan-2-one + pyruvate
? + CO2
-
-
-
?
1-(naphthalen-2-yloxy)propan-2-one + pyruvate
? + CO2
-
-
-
?
2-acetyl-2-hydroxycyclohexanone + pyruvate
1-(1-hydroxycyclohexyl)ethanone + CO2
-
-
-
-
?
2-fluorobenzaldehyde + pyruvate
(R)-1-hydroxy-1-(2-fluorophenyl)propan-2-one + CO2
-
-
-
-
?
2-hydroxybenzaldehyde + pyruvate
(R)-1-hydroxy-1-(2-hydroxyphenyl)propan-2-one + CO2
-
-
-
-
?
2-iodobenzaldehyde + pyruvate
(R)-1-hydroxy-1-(2-iodophenyl)propan-2-one + CO2
-
-
-
-
?
2-methoxybenzaldehyde + pyruvate
(R)-1-hydroxy-1-(2-methoxyphenyl)propan-2-one + CO2
-
-
-
-
?
2-methylbenzaldehyde + pyruvate
(R)-1-hydroxy-1-(2-methylphenyl)propan-2-one + CO2
-
-
-
-
?
2-naphthaldehyde + pyruvate
(1R)-1-hydroxy-1-(naphthalen-2-yl)propan-2-one + CO2
-
-
-
-
?
2-nitrobenzaldehyde + pyruvate
(R)-1-hydroxy-1-(2-nitrophenyl)propan-2-one + CO2
-
-
-
-
?
2-oxobutanoate + lactylthiamine diphosphate
acetohydroxybutanoate + ?
-
-
-
?
2-oxobutanoate + pyruvate
2-propionyl-2-hydroxybutanoate + ?
-
reaction catalyzed by mutant V375A
-
-
?
2-oxobutyrate
2-ethyl-2-hydroxy-3-oxopentanoate + CO2
-
-
-
ir
2-oxobutyrate + pyruvate
2-aceto-2-hydroxybutyrate + CO2
-
-
-
?
3,4-dihydronaphthalen-2(1H)-one + pyruvate
? + CO2
-
-
-
?
4-(tert-butyl)benzaldehyde + pyruvate
(R)-1-hydroxy-1-(4-(tert-butyl)phenyl)propan-2-one + CO2
-
-
-
-
?
4-ethoxybenzaldehyde + pyruvate
(R)-1-hydroxy-1-(4-ethoxyphenyl)propan-2-one + CO2
-
-
-
-
?
4-ethylbenzaldehyde + pyruvate
(R)-1-hydroxy-1-(4-ethylphenyl)propan-2-one + CO2
-
-
-
-
?
4-isopropylbenzaldehyde + pyruvate
(R)-1-hydroxy-1-(4-isopropylphenyl)propan-2-one + CO2
-
-
-
-
?
4-phenylbenzaldehyde + pyruvate
(R)-1-hydroxy-1-(4-ethylphenyl)propan-2-one + CO2
-
-
-
-
?
dihydro-2H-pyran-3(4H)-one + pyruvate
1-(3-hydroxytetrahydro-2H-pyran-3-yl)ethanone + CO2
-
-
-
-
?
hexane-3,4-dione + pyruvate
(S)-3-ethyl-3-hydroxyhexane-2,4-dione + CO2
-
-
-
-
?
pyruvate + 2-oxobutyrate
(S)-acetohydroxybutyrate + CO2
-
stereospecific reaction
-
-
?
pyruvate + 2-oxobutyrate
2-acetohydroxybutyrate + CO2
-
-
-
?
pyruvate + cyclohexane-1,2-dione
?
-
although cyclohexane-1,2-dione is a substrate of a C-C bond-cleavage reaction catalyzed by CDH, EC 3.7.1.11, wild-type CDH is unable to catalyze C-C bond formation (carboligation) using pyruvate as acyl anion donor and cyclohexane-1,2-dione as the acceptor. The formation of a tertiary alcohol is catalyzed by the enzyme double mutant CDH-H28A/N484A
-
-
?
pyruvate + O2
peracetate + CO2
-
isozymes AHAS II and AHAS III, oxygen-consuming side reaction
-
-
?
1-(1,3-benzodioxol-5-yloxy)propan-2-one + pyruvate
? + CO2
-
-
-
?
1-(1,3-benzodioxol-5-yloxy)propan-2-one + pyruvate
? + CO2
-
-
-
?
1-naphthaldehyde + pyruvate
(1R)-1-hydroxy-1-(naphthalen-1-yl)propan-2-one + CO2
-
-
-
-
?
1-naphthaldehyde + pyruvate
(1R)-1-hydroxy-1-(naphthalen-1-yl)propan-2-one + CO2
-
-
-
-
?
1-phenoxypropan-2-one + pyruvate
3-hydroxy-3-methyl-4-phenoxybutan-2-one + CO2
-
-
-
-
?
1-phenoxypropan-2-one + pyruvate
3-hydroxy-3-methyl-4-phenoxybutan-2-one + CO2
-
-
-
-
?
2 butane-2,3-dione
acetylacetoin + acetoin
-
homocoupling of butane-2,3-dione by the wild-type enzyme, no activity with mutant H28A/N484A
-
-
?
2 butane-2,3-dione
acetylacetoin + acetoin
-
homocoupling of butane-2,3-dione by the wild-type enzyme, no activity with mutant H28A/N484A
-
-
?
2 pyruvate
(S)-acetoin + 2 CO2
-
enzymatic formation of highly enantioenriched acetoin from two molecules of pyruvate occurs without the release of acetaldehyde or acetolactate
87-90%ee
-
?
2 pyruvate
(S)-acetoin + 2 CO2
-
in the absence of aldehydes, CDH catalyzes the decarboxylation and homocoupling of pyruvate to provide (S)-acetoin (3-hydroxybutan-2-one) with remarkably high enantioselectivity (up to 93%ee)
-
-
?
2 pyruvate
(S)-acetoin + 2 CO2
-
in the absence of aldehydes, CDH catalyzes the decarboxylation and homocoupling of pyruvate to provide (S)-acetoin (3-hydroxybutan-2-one) with remarkably high enantioselectivity (up to 93%ee)
-
-
?
2 pyruvate
(S)-acetoin + 2 CO2
-
enzymatic formation of highly enantioenriched acetoin from two molecules of pyruvate occurs without the release of acetaldehyde or acetolactate
87-90%ee
-
?
2 pyruvate
2-acetolactate + CO2
-
acetohydroxyacid synthase is the enzyme that catalyses the first step in the common pathway of the biosynthesis of the branched chain amino acids, valine, leucine and isoleucine
-
-
?
2 pyruvate
2-acetolactate + CO2
-
60fold higher specificity for 2-ketobutyrate over pyruvate as acceptor
-
-
?
2 pyruvate
2-acetolactate + CO2
irreversible decarboxylation of pyruvate
-
-
ir
2 pyruvate
2-acetolactate + CO2
AHAS catalyzes the first common step in the biosynthetic pathway of the branched-amino acids leucine, isoleucine, and valine
-
-
?
2 pyruvate
2-acetolactate + CO2
-
-
-
?
2 pyruvate
2-acetolactate + CO2
catalytic subunit ilvG shows positive cooperativity towards substrate and cofactors
-
-
?
2 pyruvate
2-acetolactate + CO2
irreversible decarboxylation of pyruvate
-
-
ir
2 pyruvate
2-acetolactate + CO2
catalytic subunit ilvG shows positive cooperativity towards substrate and cofactors
-
-
?
2 pyruvate
2-acetolactate + CO2
irreversible decarboxylation of pyruvate
-
-
ir
2 pyruvate
2-acetolactate + CO2
-
irreversible decarboxylation of pyruvate
-
-
ir
2 pyruvate
2-acetolactate + CO2
-
product decarboxylates spontaneously to final product acetoin (i.e. 3-hydroxybutanone), which is a major product at temperatures below 80°C. Acetolactate synthase ALS, which is involved in branched-chain amino acid biosynthesis, is responsible and deletion of the Als gene abolishes acetoin production
-
?
2 pyruvate
2-acetolactate + CO2
the enzyme produces 2-acetolactate in a temperature-dependent manner
-
-
?
2 pyruvate
2-acetolactate + CO2
activated enzyme ALS catalyzes the condensation and decarboxylation of two pyruvates to one 2-acetolactate
-
-
?
2 pyruvate
2-acetolactate + CO2
-
irreversible decarboxylation of pyruvate
-
-
ir
2 pyruvate
2-acetolactate + CO2
-
irreversible decarboxylation of pyruvate
-
-
ir
2-bromobenzaldehyde + pyruvate
(R)-1-hydroxy-1-(2-bromophenyl)propan-2-one + CO2
-
-
-
-
?
2-bromobenzaldehyde + pyruvate
(R)-1-hydroxy-1-(2-bromophenyl)propan-2-one + CO2
-
-
-
-
?
2-chlorobenzaldehyde + pyruvate
(R)-1-hydroxy-1-(2-chlorophenyl)propan-2-one + CO2
-
-
-
-
?
2-chlorobenzaldehyde + pyruvate
(R)-1-hydroxy-1-(2-chlorophenyl)propan-2-one + CO2
-
-
-
-
?
2-oxobutanoate + pyruvate
2-hydroxy-2-methyl-3-oxopentanoate + CO2
-
-
-
-
?
2-oxobutanoate + pyruvate
2-hydroxy-2-methyl-3-oxopentanoate + CO2
-
-
-
-
?
2-oxobutanoate + pyruvate
2-hydroxy-2-methyl-3-oxopentanoate + CO2
-
60fold higher specificity for 2-ketobutyrate over pyruvate as acceptor
-
-
?
2-oxobutanoate + pyruvate
2-hydroxy-2-methyl-3-oxopentanoate + CO2
-
-
-
?
2-oxobutanoate + pyruvate
2-hydroxy-2-methyl-3-oxopentanoate + CO2
-
-
-
-
?
2-oxobutyrate + pyruvate
(S)-2-aceto-2-hydroxybutyrate + CO2
-
-
-
?
2-oxobutyrate + pyruvate
(S)-2-aceto-2-hydroxybutyrate + CO2
-
-
-
-
?
pyruvate
(S)-2-acetolactate + CO2
-
the enzyme is the first common enzyme in the pathway for the biosynthesis of branched-chain amino acids, overview
-
-
?
pyruvate
(S)-2-acetolactate + CO2
stereospecific reaction
-
-
?
pyruvate
(S)-2-acetolactate + CO2
the enzyme is the first common enzyme in the pathway for the biosynthesis of branched-chain amino acids, overview
-
-
?
pyruvate
2-acetolactate + CO2
-
the enzyme catalyzes the first committed step in the biosynthesis of valine, leucine, and isoleucine
-
-
?
pyruvate
2-acetolactate + CO2
-
the enzyme catalyzes the first committed step in the biosynthesis of valine, leucine, and isoleucine, overview
-
-
?
pyruvate
2-acetolactate + CO2
-
first step in the biosynthesis of valine, overview
-
-
r
pyruvate
2-acetolactate + CO2
-
the enzyme catalyzes the first committed step in the biosynthesis of valine, leucine, and isoleucine
-
-
?
pyruvate
2-acetolactate + CO2
-
the enzyme catalyzes the first committed step in the biosynthesis of valine, leucine, and isoleucine, regulation, overview
-
-
?
pyruvate
2-acetolactate + CO2
-
first committed step in the biosynthesis of valine and leucine
-
-
?
pyruvate
2-acetolactate + CO2
-
the enzyme catalyzes the first committed step in the biosynthesis of valine, leucine, and isoleucine
-
-
?
pyruvate
2-acetolactate + CO2
-
first committed step in the biosynthesis of valine and leucine
-
-
?
pyruvate
2-acetolactate + CO2
-
the enzyme catalyzes the first committed step in the biosynthesis of valine, leucine, and isoleucine
-
-
?
pyruvate
2-acetolactate + CO2
-
-
-
-
?
pyruvate
2-acetolactate + CO2
-
the enzyme catalyzes the first committed step in the biosynthesis of valine, leucine, and isoleucine
-
-
?
pyruvate
2-acetolactate + CO2
-
the enzyme catalyzes the first committed step in the biosynthesis of valine, leucine, and isoleucine
-
-
r
pyruvate
2-acetolactate + CO2
-
the enzyme catalyzes the first committed step in the biosynthesis of valine, leucine, and isoleucine
-
-
?
pyruvate
2-acetolactate + CO2
-
-
-
?
pyruvate
2-acetolactate + CO2
-
-
-
?
pyruvate
2-acetolactate + CO2
-
-
-
?
pyruvate
2-acetolactate + CO2
-
-
-
?
pyruvate
?
-
first enzyme unique to biosynthesis of the branched chain amino acids Val, Leu, and Ile
-
-
?
pyruvate
?
-
the expression is negatively controlled by Val. Leu and Ile slightly stimulate the enzyme production
-
-
?
pyruvate
?
-
first enzyme unique to biosynthesis of the branched chain amino acids Val, Leu, and Ile
-
-
?
pyruvate
?
-
production of isoenzyme AHS I is under multivalent control by Val and Leu, production of isoenzyme AHS II is under multivalent control by Ile, Val and Leu
-
-
?
pyruvate
?
-
isoenzyme AHAS I enables a bacterium to cope with poor carbon sources, which lead to low endogenous pyruvate concentrations
-
-
?
pyruvate
?
-
first enzyme unique to biosynthesis of the branched chain amino acids Val, Leu, and Ile
-
-
?
pyruvate
?
-
first enzyme unique to biosynthesis of the branched chain amino acids Val, Leu, and Ile
-
-
?
pyruvate
?
-
constitutive high expression, the enzyme is active only under conditions of pyruvate excess
-
-
?
pyruvate
?
-
catabolic enzyme is involved in 2,3-butanediol pathway
-
-
?
pyruvate
?
-
first enzyme unique to biosynthesis of the branched chain amino acids Val, Leu, and Ile
-
-
?
pyruvate
?
-
isoenzyme II is regulated by Leu, Ile and Val
-
-
?
pyruvate
?
-
isoenzyme II is regulated by Leu
-
-
?
pyruvate
?
-
isoenzyme AHAS I enables a bacterium to cope with poor carbon sources, which lead to low endogenous pyruvate concentrations
-
-
?
pyruvate
?
-
first enzyme unique to biosynthesis of the branched chain amino acids Val, Leu, and Ile
-
-
?
pyruvate
?
-
isoenzyme I is regulated by Leu and Val
-
-
?
pyruvate
?
-
the enzyme plays a role in not only preventing intracellular acidification but also supplying alpha-acetolactate as an intermediate of branched chain amino acids biosynthesis
-
-
?
pyruvate
?
-
catabolic enzyme is involved in 2,3-butanediol pathway
-
-
?
pyruvate
?
-
first enzyme unique to biosynthesis of the branched chain amino acids Val, Leu, and Ile
-
-
?
pyruvate
?
-
first enzyme unique to biosynthesis of the branched chain amino acids Val, Leu, and Ile
-
-
?
pyruvate + 2-oxobutanoate
acetohydroxybutanoate
-
isoenzyme I shows no product preference, isoenzymes II and III form acetohydroxybutanoate at 180fold and 60fold faster rates, respectively than acetolactate
-
?
pyruvate + 2-oxobutanoate
acetohydroxybutanoate
-
much higher affinity for 2-oxobutanoate than for pyruvate
-
?
pyruvate + 2-oxobutanoate
acetohydroxybutanoate
-
preference for 2-ketobutanoate at the second substrate site
-
?
pyruvate + 2-oxobutanoate
acetohydroxybutanoate
-
isoenzyme I shows no product preference, isoenzymes II and III form acetohydroxybutanoate at 180fold and 60fold faster rates, respectively than acetolactate
-
?
pyruvate + 2-oxobutanoate
acetohydroxybutanoate
-
preference for 2-ketobutanoate at the second substrate site
-
?
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
-
-
-
?
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
irreversible decarboxylation of pyruvate
-
-
ir
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
-
-
-
?
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
-
-
-
?
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
-
-
-
-
?
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
-
-
-
ir
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
-
-
-
ir
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
-
first committed step in the biosynthesis of isoleucine
-
-
?
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
irreversible decarboxylation of pyruvate
-
-
ir
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
-
-
-
ir
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
-
-
-
-
?
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
-
first committed step in the biosynthesis of isoleucine
-
-
?
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
-
-
-
ir
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
irreversible decarboxylation of pyruvate
-
-
ir
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
-
irreversible decarboxylation of pyruvate
-
-
ir
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
-
-
-
?
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
-
irreversible decarboxylation of pyruvate
-
-
ir
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
-
irreversible decarboxylation of pyruvate
-
-
ir
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
-
-
-
?
pyruvate + 2-oxobutyrate
acetohydroxybutyrate + CO2
-
-
-
-
?
pyruvate + 2-oxobutyrate
acetohydroxybutyrate + CO2
-
-
-
-
?
pyruvate + benzaldehyde
(R)-phenylacetylcarbinol + CO2
-
asymmetric benzoin condensation between benzaldehyde and pyruvate
(R)-configuration with over 99% ee
-
?
pyruvate + benzaldehyde
(R)-phenylacetylcarbinol + CO2
-
The enzyme is able to catalyze nonphysiological asymmetric C-C bond formation, the cross-benzoin reaction of benzaldehyde and pyruvate (after decarboxylation) to result in the R-configured 1-hydroxy-1-phenylpropan-2-one (98% ee)
i.e. (R)-1-hydroxy-1-phenylpropan-2-one
-
?
pyruvate + benzaldehyde
(R)-phenylacetylcarbinol + CO2
-
asymmetric benzoin condensation between benzaldehyde and pyruvate
(R)-configuration with over 99% ee
-
?
pyruvate + benzaldehyde
(R)-phenylacetylcarbinol + CO2
-
The enzyme is able to catalyze nonphysiological asymmetric C-C bond formation, the cross-benzoin reaction of benzaldehyde and pyruvate (after decarboxylation) to result in the R-configured 1-hydroxy-1-phenylpropan-2-one (98% ee)
i.e. (R)-1-hydroxy-1-phenylpropan-2-one
-
?
pyruvate + benzaldehyde
(R)-phenylacetylcarbinol + CO2
-
stereospecific reaction
-
-
?
pyruvate + benzaldehyde
(R)-phenylacetylcarbinol + CO2
-
stereospecific reaction, benzaldehyde is an artificial substrate, especially of mutants of isozyme AHAS II residues Phe109, Met250, Arg276 and Trp464
-
-
?
pyruvate + benzaldehyde
(R)-phenylacetylcarbinol + CO2
-
stereospecific reaction, isozymes AHAS I and II
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pyruvate + benzaldehyde
(R)-phenylacetylcarbinol + CO2
asymmetric benzoin condensation between benzaldehyde and pyruvate
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pyruvate + benzaldehyde
(R)-phenylacetylcarbinol + CO2
asymmetric benzoin condensation between benzaldehyde and pyruvate
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additional information
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AHAS catalyses the first step leading to all three branched-chain amino acids, in the reactions, enzyme-bound thiamine diphosphate reacts with pyruvate, releasing CO2 and forming an acetaldehyde moiety as enzyme-bound hydroxyethyl-ThDP, resonating enamine/alpha-carbanion intermediate
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additional information
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the enzyme catalyzes the C-C bond cleavage of cyclohexane-1,2-dione to 6-oxohexanoate, EC 3.7.1.11, and the asymmetric benzoin condensation between benzaldehyde and pyruvate
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additional information
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in addition to its physiological C-C bond-cleavage activity, CDH catalyzes the asymmetric cross-benzoin reaction of a broad variety of aromatic aldehydes and pyruvate. In the case of the sterically demanding 4-(tert-butyl)benzaldehyde and 2-naphthaldehyde, the respective 2-hydroxyketone products are obtained in high yield. The recombinant CDH shows the same C-C bond-cleavage and C-C bond-formation activity as the enzyme purified from its native source, Azoarcus sp. strain 22Lin. Enzyme CDH catalyzes the asymmetric cross-benzoin reaction of aromatic aldehydes and (decarboxylated) pyruvate (up to quantitative conversion, 92-99% ee). The enzyme accepts also hydroxybenzaldehydes and nitrobenzaldehydes. On a semipreparative scale, sterically demanding 4-(tert-butyl)benzaldehyde and 2-naphthaldehyde are transformed into the corresponding 2-hydroxy ketone products in high yields, enzyme substrate specificity and enantioselectivity, overview
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additional information
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ThDP-dependent cyclohexane-1,2-dione hydrolase (CDH) is able to form (S)-acetoin with particularly high enantioselectivity (up to 95%ee) by all three possible pathways: homocoupling of pyruvate, homocoupling of acetaldehyde, or cross-coupling of acetaldehyde (as acceptor) and pyruvate (as donor), high enantioselectivity in the CDH-catalyzed formation of (S)-acetoin. An unprecedented non-acetolactate pathway for the homocoupling of pyruvate explains the high enantioselectivity in the CDH-catalyzed formation of (S)-acetoin, enzymatic formation of highly enantioenriched acetoin from two molecules of pyruvate occurs without the release of acetaldehyde or acetolactate, competition assay, mechanism, overview
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additional information
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the enzyme catalyzes the C-C bond cleavage of cyclohexane-1,2-dione to 6-oxohexanoate, EC 3.7.1.11, and the asymmetric benzoin condensation between benzaldehyde and pyruvate
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additional information
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in addition to its physiological C-C bond-cleavage activity, CDH catalyzes the asymmetric cross-benzoin reaction of a broad variety of aromatic aldehydes and pyruvate. In the case of the sterically demanding 4-(tert-butyl)benzaldehyde and 2-naphthaldehyde, the respective 2-hydroxyketone products are obtained in high yield. The recombinant CDH shows the same C-C bond-cleavage and C-C bond-formation activity as the enzyme purified from its native source, Azoarcus sp. strain 22Lin. Enzyme CDH catalyzes the asymmetric cross-benzoin reaction of aromatic aldehydes and (decarboxylated) pyruvate (up to quantitative conversion, 92-99% ee). The enzyme accepts also hydroxybenzaldehydes and nitrobenzaldehydes. On a semipreparative scale, sterically demanding 4-(tert-butyl)benzaldehyde and 2-naphthaldehyde are transformed into the corresponding 2-hydroxy ketone products in high yields, enzyme substrate specificity and enantioselectivity, overview
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additional information
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ThDP-dependent cyclohexane-1,2-dione hydrolase (CDH) is able to form (S)-acetoin with particularly high enantioselectivity (up to 95%ee) by all three possible pathways: homocoupling of pyruvate, homocoupling of acetaldehyde, or cross-coupling of acetaldehyde (as acceptor) and pyruvate (as donor), high enantioselectivity in the CDH-catalyzed formation of (S)-acetoin. An unprecedented non-acetolactate pathway for the homocoupling of pyruvate explains the high enantioselectivity in the CDH-catalyzed formation of (S)-acetoin, enzymatic formation of highly enantioenriched acetoin from two molecules of pyruvate occurs without the release of acetaldehyde or acetolactate, competition assay, mechanism, overview
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additional information
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enzyme additionallly displays 2-ketoisovalerate decarboxylase activity
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additional information
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enzyme additionallly displays 2-ketoisovalerate decarboxylase activity
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additional information
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enzyme AlsS catalyzes the condensation of two pyruvate molecules to acetolactate with thiamine diphosphate and Mg2+ as cofactors. The enzyme also catalyzes the conversion of 2-ketoisovalerate into isobutyraldehyde, the immediate precursor of isobutanol
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additional information
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enzyme AlsS catalyzes the condensation of two pyruvate molecules to acetolactate with thiamine diphosphate and Mg2+ as cofactors. The enzyme also catalyzes the conversion of 2-ketoisovalerate into isobutyraldehyde, the immediate precursor of isobutanol
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additional information
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acetolactate synthase AlsS is able to catalyze the decarboxylation of 2-oxoisovalerate both in vivo and in vitro
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additional information
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acetolactate synthase AlsS is able to catalyze the decarboxylation of 2-oxoisovalerate both in vivo and in vitro
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additional information
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acetolactate synthase AlsS is able to catalyze the decarboxylation of 2-oxoisovalerate both in vivo and in vitro
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additional information
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enzyme AlsS catalyzes the condensation of two pyruvate molecules to acetolactate with thiamine diphosphate and Mg2+ as cofactors. The enzyme also catalyzes the conversion of 2-ketoisovalerate into isobutyraldehyde, the immediate precursor of isobutanol
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additional information
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AHAS catalyses the first step leading to all three branched-chain amino acids, in the reactions, enzyme-bound thiamine diphosphate reacts with pyruvate, releasing CO2 and forming an acetaldehyde moiety as enzyme-bound hydroxyethyl-ThDP, resonating enamine/alpha-carbanion intermediate
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additional information
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mechanism of expression regulation, overview
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additional information
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acetohydroxybutyrate is preferably formed, isozyme AHAS I can also form peracetate from synthetic acetolactate
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additional information
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substrate specificity ratios of isozymes I-III, substrate recognition mechanism, overview
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additional information
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AHAS catalyses the first step leading to all three branched-chain amino acids, in the reactions, enzyme-bound thiamine diphosphate reacts with pyruvate, releasing CO2 and forming an acetaldehyde moiety as enzyme-bound hydroxyethyl-ThDP, resonating enamine/alpha-carbanion intermediate
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additional information
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the specificity of AHAS for 2-ketoacids as acceptor substrates is due to an arginine residue which probably interacts with the carboxylate of the second substrate, e.g., Arg276 in AHAS II. Mutants altered at this arginine can utilize aromatic aldehydes as second substrate and form chiral arylacyl carbinols. Mechanistically, carboligation occurs after rate-determining formation of hydroxyethyl-thiamine diphosphate. A faster rate constant for product release when the alkyl group derived from the acceptor substrate is ethyl compared to methyl plays a major role in product specificity. The crucial role of a Trp residue, i.e. Trp 464 in AHAS II, in determining specificity may be due to control of a conformational change involved in product release rather than to affinity for 2-ketobutyrate
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additional information
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a valine and a phenylalanine residue hydrophobically interact with the methyl substituent of pyruvate. A mutation of either Val375 or Phe109 is detrimental for unimolecular catalytic steps in which tetrahedral intermediates are involved, such as substrate addition to the cofactor and product liberation. Val375 and Phe109 to not only conjointly mediate substrate binding and specificity but moreover to ensure a proper orientation of the donor substrate and intermediates for correct orbital alignment in multiple transition states
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additional information
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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
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additional information
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residue Glu47 has a crucial catalytic role for it in the carboligation of the acceptor and the hydroxyethyl-thiamine diphosphate enamine intermediate. The Glu47-cofactor proton shuttle acts in concert with Gln110 in the carboligation. Either the transient oxyanion on the acceptor carbonyl is stabilized by H-bonding to the glutamine side chain, or carboligation involves glutamine tautomerization and the elementary reactions of addition and protonation occur in a concerted manner. Gln110 and Glu47 have global catalytic roles, being engaged in all major bond-breaking and bond-making steps. Lys159 has a minor effect on the kinetics and specificity of isoform AHAS II, far less than does Arg276,which influences the specificity for a 2-ketoacid as a second substrate. His251 has a large effect on donor substrate binding, but this effect masks any other effects of replacement of His251
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additional information
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P00892; P0ADG1
the product of this enzyme-catalyzed reaction is either 2-acetolactate or 2-aceto-2-hydroxybutyrate obtained from self-condensation of pyruvate or condensation of pyruvate and 2-oxobutyrate, respectively. Substrate specificities of isozymes: isozymes AHAS II and AHAS III prefer 2-oxobutyrate as the second substrate whereas such selectivity is not observed in case of isozyme AHAS I. Isozymes AHAS I and AHAS II are capable of self condensing 2-oxobutyrate to form 2-ethyl-2-hydroxy-3-oxopentanoate
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additional information
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the product of this enzyme-catalyzed reaction is either 2-acetolactate or 2-aceto-2-hydroxybutyrate obtained from self-condensation of pyruvate or condensation of pyruvate and 2-oxobutyrate, respectively. Substrate specificities of isozymes: isozymes AHAS II and AHAS III prefer 2-oxobutyrate as the second substrate whereas such selectivity is not observed in case of isozyme AHAS I. Isozymes AHAS I and AHAS II are capable of self condensing 2-oxobutyrate to form 2-ethyl-2-hydroxy-3-oxopentanoate
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additional information
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the product of this enzyme-catalyzed reaction is either 2-acetolactate or 2-aceto-2-hydroxybutyrate obtained from self-condensation of pyruvate or condensation of pyruvate and 2-oxobutyrate, respectively. Substrate specificities of isozymes: isozymes AHAS II and AHAS III prefer 2-oxobutyrate as the second substrate whereas such selectivity is not observed in case of isozyme AHAS I. Isozymes AHAS I and AHAS II are capable of self condensing 2-oxobutyrate to form 2-ethyl-2-hydroxy-3-oxopentanoate
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additional information
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regulatory role of the proteins of the phosphoenolpyruvate:carbohydrate phosphotransferase system, requirement of the dephospho-form of enzyme IIANtr, encoded by gene ptsN, for derepression of Escherichia coli K-12 ilvBN expression, overview
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additional information
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AHAS catalyses the first step leading to all three branched-chain amino acids, in the reactions, enzyme-bound thiamine diphosphate reacts with pyruvate, releasing CO2 and forming an acetaldehyde moiety as enzyme-bound hydroxyethyl-ThDP, resonating enamine/alpha-carbanion intermediate
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additional information
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AHAS catalyses the first step leading to all three branched-chain amino acids, in the reactions, enzyme-bound thiamine diphosphate reacts with pyruvate, releasing CO2 and forming an acetaldehyde moiety as enzyme-bound hydroxyethyl-ThDP, resonating enamine/alpha-carbanion intermediate
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additional information
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detection of nonenzymatic acetoin formation from acetolactate in the assay
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additional information
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detection of nonenzymatic acetoin formation from acetolactate in the assay
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additional information
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detection of nonenzymatic acetoin formation from acetolactate in the assay
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additional information
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the product of this enzyme-catalyzed reaction is either 2-acetolactate or 2-aceto-2-hydroxybutyrate obtained from self-condensation of pyruvate or condensation of puruvate and 2-ketobutyrate, respectively
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additional information
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the product of this enzyme-catalyzed reaction is either 2-acetolactate or 2-aceto-2-hydroxybutyrate obtained from self-condensation of pyruvate or condensation of puruvate and 2-ketobutyrate, respectively
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additional information
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the product of this enzyme-catalyzed reaction is either 2-acetolactate or 2-aceto-2-hydroxybutyrate obtained from self-condensation of pyruvate or condensation of puruvate and 2-ketobutyrate, respectively
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additional information
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the enzyme can act in anabolic or in catabolic function, the first enzyme contains the conserved motif 372RFDDR376, while the latter does not, the conserved motif 372RFDDR376 is a possible determinant of the FAD-dependent and herbicide-resistant properties of tobacco, overview
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additional information
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AHAS catalyses the first step leading to all three branched-chain amino acids, in the reactions, enzyme-bound thiamine diphosphate reacts with pyruvate, releasing CO2 and forming an acetaldehyde moiety as enzyme-bound hydroxyethyl-ThDP, resonating enamine/alpha-carbanion intermediate
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additional information
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AHAS catalyses the first step leading to all three branched-chain amino acids, in the reactions, enzyme-bound thiamine diphosphate reacts with pyruvate, releasing CO2 and forming an acetaldehyde moiety as enzyme-bound hydroxyethyl-ThDP, resonating enamine/alpha-carbanion intermediate
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additional information
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acetolactate synthase is the first common enzyme in the biosynthetic pathway of branched-chain amino acids
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additional information
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acetolactate synthase is the first common enzyme in the biosynthetic pathway of branched-chain amino acids
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additional information
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the product of this enzyme-catalyzed reaction is either 2-acetolactate or 2-aceto-2-hydroxybutyrate obtained from self-condensation of pyruvate or condensation of puruvate and 2-ketobutyrate, respectively
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additional information
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non-enzymatic decarboxylation of acetolactate to acetoin
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additional information
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non-enzymatic decarboxylation of acetolactate to acetoin
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additional information
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assay method with indirect quantitation of alpha-acetolactate by measuring acetoin formation
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additional information
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assay method with indirect quantitation of alpha-acetolactate by measuring acetoin formation
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additional information
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AHAS catalyses the first step leading to all three branched-chain amino acids, in the reactions, enzyme-bound thiamine diphosphate reacts with pyruvate, releasing CO2 and forming an acetaldehyde moiety as enzyme-bound hydroxyethyl-ThDP, resonating enamine/alpha-carbanion intermediate
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additional information
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the product of this enzyme-catalyzed reaction is either 2-acetolactate or 2-aceto-2-hydroxybutyrate obtained from self-condensation of pyruvate or condensation of puruvate and 2-ketobutyrate, respectively
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additional information
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AHAS catalyses the first step leading to all three branched-chain amino acids, in the reactions, enzyme-bound thiamine diphosphate reacts with pyruvate, releasing CO2 and forming an acetaldehyde moiety as enzyme-bound hydroxyethyl-ThDP, resonating enamine/alpha-carbanion intermediate
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additional information
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the product of this enzyme-catalyzed reaction is either 2-acetolactate or 2-aceto-2-hydroxybutyrate obtained from self-condensation of pyruvate or condensation of puruvate and 2-ketobutyrate, respectively
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additional information
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sll1981 functions as L-myo-inositol 1-phosphate synthase, MIPS, EC 5.5.1.4, overview
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additional information
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AHAS catalyses the first step leading to all three branched-chain amino acids, in the reactions, enzyme-bound thiamine diphosphate reacts with pyruvate, releasing CO2 and forming an acetaldehyde moiety as enzyme-bound hydroxyethyl-ThDP, resonating enamine/alpha-carbanion intermediate
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additional information
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non-enzymatic decarboxylation of acetolactate to acetoin
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additional information
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non-enzymatic decarboxylation of acetolactate to acetoin
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additional information
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Thermus thermophilus HB8 / ATCC 27634 / DSM 579
non-enzymatic decarboxylation of acetolactate to acetoin
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additional information
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YerE might posses the ability to activate non-sugar ketones for cross-benzoin condensations, performing enzymatic aldehyde-ketone cross-benzoin condensations
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additional information
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asymmetric intermolecular crossed aldehyde-ketone condensation through enzymatic carboligation reaction. Carboligation reactions catalyzed by the ThDP-dependent enzyme YerE with pyruvate and an acceptor substrate can lead to tertiary alcohols, (R)-phenylacetylcarbinol derivatives, (S )-acetolactate, and (S)-acetoin, overview
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additional information
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YerE might posses the ability to activate non-sugar ketones for cross-benzoin condensations, performing enzymatic aldehyde-ketone cross-benzoin condensations
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additional information
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asymmetric intermolecular crossed aldehyde-ketone condensation through enzymatic carboligation reaction. Carboligation reactions catalyzed by the ThDP-dependent enzyme YerE with pyruvate and an acceptor substrate can lead to tertiary alcohols, (R)-phenylacetylcarbinol derivatives, (S )-acetolactate, and (S)-acetoin, overview
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