Information on EC 4.1.1.72 - branched-chain-2-oxoacid decarboxylase

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The expected taxonomic range for this enzyme is: Bacteria, Eukaryota

EC NUMBER
COMMENTARY
4.1.1.72
-
RECOMMENDED NAME
GeneOntology No.
branched-chain-2-oxoacid decarboxylase
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
(3S)-3-methyl-2-oxopentanoate = 2-methylbutanal + CO2
show the reaction diagram
acts on a number of 2-oxo acids, with a high affinity toward branched-chain substrates. The aldehyde formed may be enzyme-bound, and may be an intermediate in the bacterial system for the biosynthesis of branched-chain fatty acids
-
-
-
(3S)-3-methyl-2-oxopentanoate = 2-methylbutanal + CO2
show the reaction diagram
binding of cofactor thiamine diphosphate to E1b component of enzyme induces a disorder-to-order transition of the conserved phosphorylation loop carrying phosphorylation sites S292 and S302
-
REACTION TYPE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
decarboxylation
-
-
-
-
PATHWAY
KEGG Link
MetaCyc Link
butanol and isobutanol biosynthesis (engineered)
-
isoleucine degradation II
-
pyruvate fermentation to isobutanol (engineered)
-
valine degradation II
-
SYSTEMATIC NAME
IUBMB Comments
(3S)-3-methyl-2-oxopentanoate carboxy-lyase (2-methylbutanal-forming)
Acts on a number of 2-oxo acids, with a high affinity towards branched-chain substrates. The aldehyde formed may be enzyme-bound, and may be an intermediate in the bacterial system for the biosynthesis of branched-chain fatty acids.
SYNONYMS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
alpha-keto acid decarboxylase
O53865
-
BCKA
-
-
-
-
branched-chain 2-keto acid decarboxylase
-
-
branched-chain 2-oxoacid decarboxylase
-
-
-
-
branched-chain alpha-keto acid decarboxylase
-
-
-
-
branched-chain alpha-ketoacid dehydrogenase complex
-
the protein complex also contains glutamate dehydrogenase 1, 4-nitrophenylphosphatase domain and non-neuronal SNAP25-like protein homolog 1, pyruvate carboxylase, and BCKDC kinase
branched-chain keto acid decarboxylase
-
-
-
-
branched-chain keto acid decarboxylase
-
-
branched-chain oxo acid decarboxylase
-
-
-
-
decarboxylase, branched-chain oxo acid
-
-
-
-
KdcA
-
has decarboxylase and carboligase activities
KdcA
Q6QBS4
-
CAS REGISTRY NUMBER
COMMENTARY
63653-19-0
-
ORGANISM
COMMENTARY
LITERATURE
SEQUENCE CODE
SEQUENCE DB
SOURCE
expressed in Lycopersicon esculentum
-
-
Manually annotated by BRENDA team
simultaneous expression of human alpha-subunit and bovine beta-subunit of enzyme in Escherichia coli
-
-
Manually annotated by BRENDA team
simultaneous expression of human alpha-subunit and bovine beta-subunit of enzyme in Escherichia coli
-
-
Manually annotated by BRENDA team
subspecies Lactococcus lactis cremoris, strain B1157
-
-
Manually annotated by BRENDA team
enzyme may be a component of an enzyme complex named alpha-ketoisocaproate:alpha-keto-beta-methylvalerate dehydrogenase
-
-
Manually annotated by BRENDA team
SUBSTRATE
PRODUCT                      
REACTION DIAGRAM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
(indol-3-yl)pyruvate
(indol-3-yl)acetaldehyde + CO2
show the reaction diagram
O53865
-
-
-
?
2-oxo-3-methylpentanoate
2-methylbutanal + CO2
show the reaction diagram
O53865
-
-
-
?
2-oxo-3-methylvalerate
2-mehylbutanal + CO2
show the reaction diagram
-
the enzymatic activity toward 2-oxo-3-methylvalerate is 1.5times higher than the activity toward 2-oxo-isovalerate
-
-
?
2-oxo-3-phenylpropanoic acid
phenylacetaldehyde + CO2
show the reaction diagram
-
at 30 mM 8.6% activity relative to 3-methyl-2-oxobutanoic acid
-
-
?
2-oxobutanoic acid
propanal + CO2
show the reaction diagram
Q6QBS4
10% of the rate with 3-methyl-2-oxobutanoic acid
-
-
?
2-oxobutanoic acid
propanal + CO2
show the reaction diagram
-
at 30 mM 9.3% activity relative to 3-methyl-2-oxobutanoic acid
-
-
?
2-oxobutyrate
propionaldehyde + CO2
show the reaction diagram
O53865
-
-
-
?
2-oxoglutarate
CO2 + succinate semialdehyde
show the reaction diagram
-
5% of the activity with L-3-methyl-2-oxopentanoate
-
-
-
2-oxohexanoate
n-pentanal + CO2
show the reaction diagram
O53865
-
-
-
?
2-oxohexanoic acid
pentanal + CO2
show the reaction diagram
Q6QBS4
30% of the rate with 3-methyl-2-oxobutanoic acid
-
-
?
2-oxohexanoic acid
pentanal + CO2
show the reaction diagram
-
at 30 mM 13% activity relative to 3-methyl-2-oxobutanoic acid
-
-
?
2-oxoisohexanoate
CO2 + isopentanal
show the reaction diagram
-
38% of the activity with L-3-methyl-2-oxopentanoate
-
-
-
2-oxoisohexanoate
CO2 + isopentanal
show the reaction diagram
-
38% of the activity with L-3-methyl-2-oxopentanoate
-
-
-
2-oxoisohexanoate
? + CO2
show the reaction diagram
O53865
-
-
-
?
2-oxoisopentanoate
CO2 + isobutanal
show the reaction diagram
-
not
-
-
-
2-oxoisopentanoate
CO2 + isobutanal
show the reaction diagram
-
63% of the activity with L-3-methyl-
-
-
?
2-oxoisopentanoate
2-methylpropanal + CO2
show the reaction diagram
O53865
-
-
-
?
2-oxoisovalerate
2-methylpropanal + CO2
show the reaction diagram
-
-
-
-
?
2-oxopentanoate
n-butanal + CO2
show the reaction diagram
O53865
-
-
-
?
2-oxopentanoic acid
butanal + CO2
show the reaction diagram
Q6QBS4
25% of the rate with 3-methyl-2-oxobutanoic acid
-
-
?
2-oxopentanoic acid
butanal + CO2
show the reaction diagram
-
at 30 mM 15% activity relative to 3-methyl-2-oxobutanoic acid
-
-
?
2-oxopropanoic acid
acetaldehyde + CO2
show the reaction diagram
-
at 30 mM 1.2% activity relative to 3-methyl-2-oxobutanoic acid
-
-
?
3-(4-hydroxyphenyl)-2-oxopropanoic acid
(4-hydroxyphenyl)-acetaldehyde + CO2
show the reaction diagram
-
at 30 mM 6% activity relative to 3-methyl-2-oxobutanoic acid
-
-
?
3-methyl-2-oxobutanoic acid
2-methylpropanal + CO2
show the reaction diagram
-
-
-
-
?
3-methyl-2-oxobutanoic acid
2-methylpropanal + CO2
show the reaction diagram
Q6QBS4
-
-
-
?
3-methyl-2-oxobutanoic acid
2-methylpropanal + CO2
show the reaction diagram
-
100% activity
-
-
?
3-methyl-2-oxopentanoate
CO2 + 2-methylbutanal
show the reaction diagram
-
-
-
-
?
3-methyl-2-oxopentanoate
CO2 + 2-methylbutanal
show the reaction diagram
-
-
-
-
?
3-methyl-2-oxopentanoic acid
2-methylbutanal + CO2
show the reaction diagram
Q6QBS4
30% of the rate with 3-methyl-2-oxobutanoic acid
-
-
?
3-methyl-2-oxopentanoic acid
2-methylbutanal + CO2
show the reaction diagram
-
at 30 mM 38.1% activity relative to 3-methyl-2-oxobutanoic acid
-
-
?
4-(4-hydroxyphenyl)-2-oxobutanoic acid
3-(4-hydroxyphenyl)-propanal + CO2
show the reaction diagram
-
at 30 mM 1.6% activity relative to 3-methyl-2-oxobutanoic acid
-
-
?
4-(methylsulfanyl)-2-oxobutanoic acid
3-(methylsulfanyl)-propanal + CO2
show the reaction diagram
-
at 30 mM 18% activity relative to 3-methyl-2-oxobutanoic acid
-
-
?
4-hydroxyphenylpyruvate
4-hydroxyphenylacetaldehyde + CO2
show the reaction diagram
O53865
-
-
-
?
4-methyl-2-oxohexanoic acid
3-methylpentanal + CO2
show the reaction diagram
-
at 30 mM 19% activity relative to 3-methyl-2-oxobutanoic acid
-
-
?
4-methyl-2-oxopentanoic acid
3-methylbutanal + CO2
show the reaction diagram
Q6QBS4
35% of the rate with 3-methyl-2-oxobutanoic acid
-
-
?
4-methyl-2-oxopentanoic acid
3-methylbutanal + CO2
show the reaction diagram
-
at 30 mM 26.3% activity relative to 3-methyl-2-oxobutanoic acid
-
-
?
4-methylthio-2-oxobutanoic acid
3-methylthiopropanal + CO2
show the reaction diagram
Q6QBS4
10% of the rate with 3-methyl-2-oxobutanoic acid
-
-
?
5-(4-hydroxyphenyl)-2-oxopentanoic acid
4-(4-hydroxyphenyl)-butanal + CO2
show the reaction diagram
-
at 30 mM 1.1% activity relative to 3-methyl-2-oxobutanoic acid
-
-
?
alpha-isocaproic acid
3-methylbutanal + CO2
show the reaction diagram
Q6QBS4
-
-
-
?
benzaldehyde + CO2
(R)-benzoin
show the reaction diagram
-
self-carboligation
-
-
?
benzoylformate
? + CO2
show the reaction diagram
O53865
-
-
-
?
indole-3-pyruvate
?
show the reaction diagram
-
at 1 mM 0.85% activity relative to 3-methyl-2-oxobutanoic acid
-
-
?
isovaleraldehyde
?
show the reaction diagram
-
self-carboligation
-
-
?
L-3-methyl-2-oxopentanoate
CO2 + 2-methylbutanal
show the reaction diagram
-
-
-
-
?
oxo(phenyl)acetic acid
benzaldehyde + CO2
show the reaction diagram
-
at 30 mM 8.4% activity relative to 3-methyl-2-oxobutanoic acid
-
-
?
Phenylpyruvate
Phenylacetaldehyde + CO2
show the reaction diagram
O53865
-
-
-
?
Pyruvate
Acetaldehyde + CO2
show the reaction diagram
O53865
-
-
-
?
pyruvate
CO2 + ethanal
show the reaction diagram
-
25% of the activity with L-3-methyl-2-oxopentanoate
-
-
-
L-3-methyl-2-oxopentanoate
CO2 + 2-methylbutanal
show the reaction diagram
-
stereospecificity towards the L-isomer
-
-
?
additional information
?
-
-
essential for the synthesis of branched-chain fatty acids
-
-
-
additional information
?
-
-
plants with enzymic activity show enhanced cold tolerance, role as a protective mechanism for growth of plants under sub optimal temperatures
-
-
-
additional information
?
-
-
3-fluoro-2-oxopropanoic acid, isobutyraldehyde, 3,5-dichlorobenzaldehyde, 3,5-dimethoxybenzaldehyde and 2-oxooctanoic acid are no substrates
-
-
-
additional information
?
-
-
the enzyme is also able to catalyze carboligation reactions with an exceptionally broad substrate range, a feature that makes KdcA a potentially valuable biocatalyst for C-C bond formation, in particular for the enzymatic synthesis of diversely substituted 2-hydroxyketones with high enantioselectivity
-
-
-
additional information
?
-
O53865
enzyme is found to convert a broad spectrum of branched-chain and aromatic alpha-keto acids. Determined the catalytic constants for the conversion of 11 aliphatic, aromatic, and branched-chain alpha-keto acids
-
-
-
additional information
?
-
-
mitochondrial branched-chain aminotransferase binds to the E1 decarboxylase of BCKDC, forming a metabolon that allows channeling of branched-chain alpha-keto acids from mitochondrial branched-chain aminotransferase to E1
-
-
-
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
3-methyl-2-oxopentanoate
CO2 + 2-methylbutanal
show the reaction diagram
-
-
-
-
?
3-methyl-2-oxopentanoate
CO2 + 2-methylbutanal
show the reaction diagram
-
-
-
-
?
additional information
?
-
-
essential for the synthesis of branched-chain fatty acids
-
-
-
additional information
?
-
-
plants with enzymic activity show enhanced cold tolerance, role as a protective mechanism for growth of plants under sub optimal temperatures
-
-
-
COFACTOR
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
thiamine diphosphate
-
stimulates moderately
thiamine diphosphate
-
required
thiamine diphosphate
-
binds to E1b component of enzyme complex
thiamine diphosphate
-
dependent
thiamine diphosphate
O53865
-
METALS and IONS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
ferricyanide
-
stimulates
Mg2+
-
dependent
additional information
-
no requirement for MgCl2
INHIBITORS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
2-[(R)-1-hydroxyethyl]deaza thiamine diphosphate
-
0.1 mM
pyruvate
O53865
weak substrate inhibition
ACTIVATING COMPOUND
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
NaCl
Q6QBS4
20% increase in activity at 1 M
additional information
O53865
stopped-flow kinetics show that MtKDC is allosterically activated by 2-oxoacids, also amino acids are potent activators
-
additional information
-
GDH1 alone does not have a significant effect on BCKDC activity. However, addition of GDH1 and glutamate enhance the calculated kcat value by 40-45% with mitochondrial branched-chain aminotransferase present when compared with BCKDC plus branched-chain alpha-keto acids alone
-
KM VALUE [mM]
KM VALUE [mM] Maximum
SUBSTRATE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
0.09
-
(indol-3-yl)pyruvate
O53865
-
-
20.25
-
2-oxo-3-methylpentanoate
O53865
-
138.3
-
2-oxobutyrate
O53865
-
0.83
-
2-Oxohexanoate
O53865
-
0.6
-
2-oxohexanoic acid
-
in 50 mM potassium phosphate buffer, pH 6.8 in the presence of 2.5 mM MgSO4 and 0.1 mM thiamine diphosphate
2
-
2-Oxoisohexanoate
-
25C, pH 7.2
0.05
-
2-oxoisovalerate
-
mutant D295A, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction; mutant D295A, pH 7.5, 30C, overall reaction; wild-type, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction; wild-type, pH 7.5, 30C, overall reaction
0.14
-
2-oxoisovalerate
-
mutant Y300A, pH 7.5, 30C, overall reaction
0.225
-
2-oxoisovalerate
-
mutant R301A, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction
0.252
-
2-oxoisovalerate
-
mutant Y300F, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction
0.255
-
2-oxoisovalerate
-
mutant R301A, pH 7.5, 30C, overall reaction
0.337
-
2-oxoisovalerate
-
mutant Y300A, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction
0.39
-
2-oxoisovalerate
-
mutant Y300F, pH 7.5, 30C, overall reaction
1.21
-
2-Oxopentanoate
O53865
-
1.3
-
2-Oxopentanoic acid
-
in 50 mM potassium phosphate buffer, pH 6.8 in the presence of 2.5 mM MgSO4 and 0.1 mM thiamine diphosphate
29.77
-
2-Oxopropanoic acid
-
in 50 mM potassium phosphate buffer, pH 6.8 in the presence of 2.5 mM MgSO4 and 0.1 mM thiamine diphosphate
0.63
-
3-(4-hydroxyphenyl)-2-oxopropanoic acid
-
in 50 mM potassium phosphate buffer, pH 6.8 in the presence of 2.5 mM MgSO4 and 0.1 mM thiamine diphosphate
5.02
-
3-methyl-2-oxobutanoic acid
-
in 50 mM potassium phosphate buffer, pH 6.8 in the presence of 2.5 mM MgSO4 and 0.1 mM thiamine diphosphate
0.87
-
3-methyl-2-oxopentanoate
-
25C, pH 7.2
1.3
-
4-(methylsulfanyl)-2-oxobutanoic acid
-
in 50 mM potassium phosphate buffer, pH 6.8 in the presence of 2.5 mM MgSO4 and 0.1 mM thiamine diphosphate
0.264
-
4-methyl-2-oxopentanoic acid
-
in 50 mM potassium phosphate buffer, pH 6.8 in the presence of 2.5 mM MgSO4 and 0.1 mM thiamine diphosphate
26.11
-
benzoylformate
O53865
-
0.234
-
Indole-3-pyruvate
-
in 50 mM potassium phosphate buffer, pH 6.8 in the presence of 2.5 mM MgSO4 and 0.1 mM thiamine diphosphate
0.001
-
L-3-Methyl-2-oxopentanoate
-
and 2-oxoisopentanoate, 2-oxoisohexanoate, value below, 30C, pH 7.5
7.5
-
oxo(phenyl)acetic acid
-
in 50 mM potassium phosphate buffer, pH 6.8 in the presence of 2.5 mM MgSO4 and 0.1 mM thiamine diphosphate
0.127
-
phenyl pyruvate
-
in 50 mM potassium phosphate buffer, pH 6.8 in the presence of 2.5 mM MgSO4 and 0.1 mM thiamine diphosphate
1.17
-
phenylpyruvate
O53865
-
0.00063
-
thiamine diphosphate
-
wild-type, pH 7.5, 30C, overall reaction
0.0066
-
thiamine diphosphate
-
wild-type, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction
0.015
-
thiamine diphosphate
-
mutant D295A, pH 7.5, 30C, overall reaction
0.016
-
thiamine diphosphate
-
mutant D295A, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction
0.018
-
thiamine diphosphate
-
mutant Y300F, pH 7.5, 30C, overall reaction
0.026
-
thiamine diphosphate
-
mutant R301A, pH 7.5, 30C, overall reaction; mutant Y300A, pH 7.5, 30C, overall reaction
0.028
-
thiamine diphosphate
-
mutant Y300F, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction
0.029
-
thiamine diphosphate
-
mutant R301A, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction
0.04
-
thiamine diphosphate
-
mutant Y300A, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction
TURNOVER NUMBER [1/s]
TURNOVER NUMBER MAXIMUM[1/s]
SUBSTRATE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
2.98
-
(indol-3-yl)pyruvate
O53865
-
-
19.75
-
2-oxo-3-methylpentanoate
O53865
-
5.98
-
2-oxobutyrate
O53865
-
7.06
-
2-Oxohexanoate
O53865
-
31.5
-
2-Oxoisohexanoate
O53865
-
28.35
-
2-oxoisopentanoate
O53865
-
0.19
-
2-oxoisovalerate
-
wild-type, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction; wild-type, pH 7.5, 30C, overall reaction
0.38
-
2-oxoisovalerate
-
mutant Y300A, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction; mutant Y300A, pH 7.5, 30C, overall reaction
0.41
-
2-oxoisovalerate
-
mutant R301A, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction; mutant R301A, pH 7.5, 30C, overall reaction
0.48
-
2-oxoisovalerate
-
mutant D295A, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction; mutant D295A, pH 7.5, 30C, overall reaction
0.57
-
2-oxoisovalerate
-
mutant Y300F, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction; mutant Y300F, pH 7.5, 30C, overall reaction
6.95
-
2-Oxopentanoate
O53865
-
3.89
-
4-hydroxyphenylpyruvate
O53865
-
18.57
-
benzoylformate
O53865
-
7.5
-
phenylpyruvate
O53865
-
0.19
-
thiamine diphosphate
-
wild-type, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction; wild-type, pH 7.5, 30C, overall reaction
0.31
-
thiamine diphosphate
-
mutant Y300A, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction; mutant Y300A, pH 7.5, 30C, overall reaction
0.41
-
thiamine diphosphate
-
mutant R301A, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction; mutant R301A, pH 7.5, 30C, overall reaction
0.42
-
thiamine diphosphate
-
mutant D295A, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction; mutant D295A, pH 7.5, 30C, overall reaction
0.53
-
thiamine diphosphate
-
mutant Y300F, pH 7.5, 30C, E1b-catalyzed decarboxylation reaction; mutant Y300F, pH 7.5, 30C, overall reaction
Ki VALUE [mM]
Ki VALUE [mM] Maximum
INHIBITOR
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
IMAGE
124
-
pyruvate
O53865
weak substrate inhibition is detected for pyruvate
SPECIFIC ACTIVITY [µmol/min/mg]
SPECIFIC ACTIVITY MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
0.02
-
-
30C, pH 7.5
pH OPTIMUM
pH MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
6.3
-
Q6QBS4
-
7.2
-
-
assay at
pH RANGE
pH RANGE MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
6
9
-
pH 6: about 60% of maximum activity, pH 9: about 55% of maximum activity
TEMPERATURE OPTIMUM
TEMPERATURE OPTIMUM MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
25
-
-
assay at
SOURCE TISSUE
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
SOURCE
additional information
-
BCKDC proteins in the metabolon are found in all tissues except skeletal muscle, which harbors only the five subunits
Manually annotated by BRENDA team
LOCALIZATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
GeneOntology No.
LITERATURE
SOURCE
MOLECULAR WEIGHT
MOLECULAR WEIGHT MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
59780
-
O53865
calculated from the deduced amino acid sequence
126700
-
-
calculated from amino acid sequence
146000
-
-
gel filtration
160000
-
-
gel filtration
171000
-
-
with His6-tagged alpha subunits, gel filtration, sucrose density gradient
175000
-
-
gel filtration
SUBUNITS
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
?
Q6QBS4
x * 60900, calculated, x * 62000, SDS-PAGE
homodimer
-
x-ray crystallography
tetramer
-
2 * 33000, A-subunit, + 2 * 39800, B-subunit, SDS-PAGE
tetramer
-
2 * 45500, alpha subunit, + 2 * 37800, beta subunit, SDS-PAGE, enzyme forms part of the branched chain alpha-ketoacid dehydrogenase complex
tetramer
-
2 * 45000, alpha subunit, + 2 * 37000, beta subunit, SDS-PAGE
homodimer
-
2 * 73000, gel filtration
additional information
-
assembly of tetramer is promoted by chaperonins groEL and groES
additional information
-
concurrent expression of subunits alpha and beta is important for assembly
POSTTRANSLATIONAL MODIFICATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
phosphoprotein
-
when the E1alpha subunit is fully phosphorylated, overall BCKDC activity is zero
Crystallization/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
hanging drop vapour diffusion method using 25-26% (v/v) PEG 200 in 0.1 M MES buffer pH 6.2 as a precipitant
-
pH STABILITY
pH STABILITY MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
4
-
-
rapid inactivation at pH 4
5
7
-
stable at pH 5-7
8
-
-
inactivation at pH 8
TEMPERATURE STABILITY
TEMPERATURE STABILITY MAXIMUM
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
40
-
-
sufficiently stable up to 40C, but rapidly loses activity at higher temperatures
ORGANIC SOLVENT
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
DMSO
-
completely stable in the presence of 20% (v/v) DMSO (half-life: 150 h)
polyethyleneglycol
-
rapidly inactivated in the presence of 15% (v/v) PEG-400
Purification/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
immobilized metal chelate chromatography and gel filtration
-
Ni-NTA column chromatography
-
anion exchange chromatography and gel filtration
O53865
Cloned/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
expressed in Escherichia coli
-
expressed in Escherichia coli strain BL21(DE3)
-
expressed in Escherichia coli strain H-81
-
expressed in Escherichia coli Rosetta 2 (DE3) and various Escherichia coli strains
O53865
ENGINEERING
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
A240P-alpha
-
slow assembly of alpha2beta2 tetramer
D295A
-
of component E1b, 2fold increase in kcat-value
E193A-alpha
-
complete inactivation of enzyme
E76A-beta
-
complete inactivation of enzyme
F364C-alpha
-
slow assembly of enzyme, alphabeta dimer
G204S-alpha
-
slow assembly of alpha2beta2 tetramer
G245R-alpha
-
moderately slow assembly of alpha2beta2 tetramer
H146A-beta
-
complete inactivation of enzyme
H291A-alpha
-
partially active enzyme
N222S-alpha
-
normal assembly of alpha2beta2 tetramer
N222S-alpha
-
markedly higher Km value for thiamin diphosphate
R114W-alpha
-
naturally occuring mutation in maple syrup disease patients, strongly reduced binding of thiamin diphosphate, enzyme inactive
R220W-alpha
-
normal assembly of alpha2beta2 tetramer
R220W-alpha
-
naturally occuring mutation in maple syrup disease patients, strongly reduced binding of thiamin diphosphate, enzyme inactive
R287A
-
of component E1b, 40fold increase in Km-value for 2-oxoisovalerate
R301A
-
of component E1b, 4fold increase in Km-value for 2-oxoisovalerate
T166M-alpha
-
enzyme inactive, with attenuated ability to bind thiamin diphosphate
T265R
-
no assembly of alpha2beta2 tetramer
Y224A-alpha
-
markedly higher Km value for thiamin diphosphate
Y300A
-
of component E1b, 6fold increase in Km-value for 2-oxoisovalerate
Y300F
-
of component E1b, 5fold increase in Km-value for 2-oxoisovalerate
Y368C-alpha
-
slow assembly of enzyme as alphabeta dimer and alpha2beta2 tetramer
Y393N-alpha
-
slow assembly of enzyme, alphabeta dimer
Y393N-alpha
-
no assembly of heterotetramer
Renatured/COMMENTARY
ORGANISM
UNIPROT ACCESSION NO.
LITERATURE
after denaturation in 8 M urea, reconstitution at 23C with absolute requirement of chaperonins GroEL/GroES and MgATP2-
-
APPLICATION
ORGANISM
UNIPROT ACCESSION NO.
COMMENTARY
LITERATURE
agriculture
-
plants with enzymic activity show enhanced cold tolerance, role as a protective mechanism for growth of plants under sub optimal temperatures
medicine
-
naturally occuring mutations cause an impaired assembly of enzyme in patients with maple syrup urine disease
medicine
-
in patients with maple syrup urine disease, mutations such as R114W-alpha or R220W-alpha cause a strongly reduced binding of thiamin diphosphate, rendering the enzyme inactive
synthesis
-
the enzyme is able to catalyze carboligation reactions with an exceptionally broad substrate range, a feature that makes KdcA a potentially valuable biocatalyst for C-C bond formation, in particular for the enzymatic synthesis of diversely substituted 2-hydroxyketones with high enantioselectivity