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Information on EC 2.2.1.6 - acetolactate synthase and Organism(s) Mycobacterium tuberculosis and UniProt Accession O53554

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IUBMB Comments
This enzyme requires thiamine diphosphate. The reaction shown is in the pathway of biosynthesis of valine; the enzyme can also transfer the acetaldehyde from pyruvate to 2-oxobutanoate, forming 2-ethyl-2-hydroxy-3-oxobutanoate, also known as 2-aceto-2-hydroxybutanoate, a reaction in the biosynthesis of isoleucine.
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This record set is specific for:
Mycobacterium tuberculosis
UNIPROT: O53554
Word Map
The taxonomic range for the selected organisms is: Mycobacterium tuberculosis
The enzyme appears in selected viruses and cellular organisms
Reaction Schemes
Synonyms
acetohydroxy acid synthase, acetohydroxy acid synthase I, acetohydroxy acid synthetase, acetohydroxyacid synthase, acetolactate pyruvate-lyase (carboxylating), acetolactate synthase, acetolactate synthetase, acetolactic synthetase, AHAS, AHAS II, more
SYNONYM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
acetohydroxy acid synthase
acetohydroxy acid synthetase
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-
-
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acetohydroxyacid synthase
acetolactate pyruvate-lyase (carboxylating)
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-
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acetolactate synthetase
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acetolactic synthetase
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alpha-acetohydroxy acid synthetase
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alpha-acetohydroxyacid synthase
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alpha-acetolactate synthase
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alpha-acetolactate synthetase
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alpha-ALS
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-
-
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GST-mALS
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GST-wALS
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-
-
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synthase, acetolactate
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-
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REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
2 pyruvate = 2-acetolactate + CO2
show the reaction diagram
catalytic mechanism, detailed overview. An intermediate step involves the attack of the ThDP carbanion on the pyruvate to form lactyl ThDP. The second substrate (the acceptor) carbonyl is attacked by hydroxyethylthiamine diphosphate enamine to give the product-ThDP adduct, which then dissociates to form ThDP and the free product. Direct competition that exists between the acceptor substrates for the bound HE-ThDP determines the ratio of formation of the products. The product ratio depends only on the relative amounts of the acceptor substrates in wild-type enzymes and the kcat is virtually independent of the amount of the acceptors. The rate determining step of the process is the one just before product determining carboligation step from which kcat is determined, the other steps of the process have little effect on the overall rate of reaction
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
C-C bond formation
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decarboxylation
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SYSTEMATIC NAME
IUBMB Comments
pyruvate:pyruvate acetaldehydetransferase (decarboxylating)
This enzyme requires thiamine diphosphate. The reaction shown is in the pathway of biosynthesis of valine; the enzyme can also transfer the acetaldehyde from pyruvate to 2-oxobutanoate, forming 2-ethyl-2-hydroxy-3-oxobutanoate, also known as 2-aceto-2-hydroxybutanoate, a reaction in the biosynthesis of isoleucine.
CAS REGISTRY NUMBER
COMMENTARY hide
9027-45-6
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SUBSTRATE
PRODUCT                       
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
2 pyruvate
2-acetolactate + CO2
show the reaction diagram
-
-
-
?
2 pyruvate
2-acetolactate + CO2
show the reaction diagram
2-oxobutyrate + pyruvate
2-aceto-2-hydroxybutyrate + CO2
show the reaction diagram
-
-
-
-
pyruvate
2-acetolactate + CO2
show the reaction diagram
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate
show the reaction diagram
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
show the reaction diagram
additional information
?
-
NATURAL SUBSTRATE
NATURAL PRODUCT
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
2 pyruvate
2-acetolactate + CO2
show the reaction diagram
2-oxobutyrate + pyruvate
2-aceto-2-hydroxybutyrate + CO2
show the reaction diagram
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-
-
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pyruvate
2-acetolactate + CO2
show the reaction diagram
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate
show the reaction diagram
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first committed step in the biosynthesis of isoleucine
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-
?
pyruvate + 2-oxobutyrate
2-aceto-2-hydroxybutyrate + CO2
show the reaction diagram
COFACTOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
thiamine diphosphate
Ks value 0.042 mM
thiamine diphosphate
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
additional information
enzyme AHAS is not specific as far as metal ions are concerned. It is active in presence of any metal ion like Mn2+, Mg2+, Ca2+, Cd2+
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
2-chloro-3-oxocyclohex-1-en-1-yl 3-(trifluoromethyl)benzoate
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2-chloro-5,5-dimethyl-3-oxocyclohex-1-en-1-yl 4-chlorobenzoate
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2-chloro-5,5-dimethyl-3-oxocyclohex-1-en-1-yl 4-chlorobenzoic acid
no inhibition by bensulfuron methyl. Feedback inhibition takes place in the holoenzyme containing the regulatory and the catalytic subunits. The branched-chain amino acids are believed to bind only to the regulatory subunit and inhibit the enzyme. Molecular docking of benzoyl ester compounds. AHAS-inhibitors and the probable binding pattern
2-chloro-6-(methoxycarbonyl)-5,5-dimethyl-3-oxocyclohex-1-en-1-yl 4-chlorobenzoate
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2-chloro-N-(4-chloro-3-[[(4-methoxypyrimidin-2-yl)carbamoyl]sulfamoyl]phenyl)acetamide
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2-chloro-N-(4-chloro-3-[[(4-methylpyrimidin-2-yl)carbamoyl]sulfamoyl]phenyl)acetamide
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2-nitro-5-(phenylsulfonyl)phenyl 4-chlorobenzoate
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2-phenyl-3-[[3-(trifluoromethyl)benzoyl]oxy]quinazolin-4(3H)-one
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3-[(3-bromobenzoyl)oxy]-2-phenylquinazolin-4(3H)-one
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3-[(4-nitrobenzoyl)oxy]quinazolin-4(3H)-one
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4-(cyclopropylcarbonyl)-N-[(4,6-dimethoxypyrimidin-2-yl)carbamoyl]-1-methyl-1H-pyrazole-5-sulfonamide
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i.e. K13030
4-acetyl-N-[(4,6-dimethoxypyrimidin-2-yl)carbamoyl]-1-methyl-1H-pyrazole-5-sulfonamide
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i.e. K13010
chlorimuron ethyl
ethyl 4-chloro-2-[[(4-methylpyrimidin-2-yl)carbamoyl]sulfamoyl]benzoate
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isoleucine
feedback inhibition
KHG20612
leucine
feedback inhibition
methyl-2-[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)carbamoylsulfamoyl]benzoate
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metsulfuron methyl
N-phenyl-3-(phenyldisulfanyl)-1H-1,2,4-triazole-1-carboxamide
strong inhibition
N-[(4,6-dimethoxypyrimidin-2-yl)carbamoyl]-2-(ethylsulfanyl)-6-(2-fluoro-1-hydroxyethyl)benzenesulfonamide
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i.e. K12147
primisulfuron methyl
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IC50: 0.0042 mM, over 80% inhibition at 0.04 mM
propan-2-yl 4-bromo-3-[[(4-methylpyrimidin-2-yl)carbamoyl]sulfamoyl]benzoate
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pyrazosulfuron ethyl
sulfometuron methyl
valine
additional information
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KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.0028 - 807.7
pyruvate
additional information
additional information
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kinetics
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TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.0026 - 3.2
pyruvate
kcat/KM VALUE [1/mMs-1]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.205 - 1158
pyruvate
Ki VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
16.3
valine
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pH 7.0, 37C, holoenzyme
additional information
additional information
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inhibition kinetics of sulfonylurea herbicides
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IC50 VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.00267
2-chloro-3-oxocyclohex-1-en-1-yl 3-(trifluoromethyl)benzoate
Mycobacterium tuberculosis
pH and temperature not specified in the publication
0.0141
2-chloro-5,5-dimethyl-3-oxocyclohex-1-en-1-yl 4-chlorobenzoate
Mycobacterium tuberculosis
pH and temperature not specified in the publication
0.00178
2-chloro-6-(methoxycarbonyl)-5,5-dimethyl-3-oxocyclohex-1-en-1-yl 4-chlorobenzoate
Mycobacterium tuberculosis
pH and temperature not specified in the publication
0.00202
2-phenyl-3-[[3-(trifluoromethyl)benzoyl]oxy]quinazolin-4(3H)-one
Mycobacterium tuberculosis
pH and temperature not specified in the publication
0.00185
3-[(3-bromobenzoyl)oxy]-2-phenylquinazolin-4(3H)-one
Mycobacterium tuberculosis
pH and temperature not specified in the publication
0.01413
3-[(4-nitrobenzoyl)oxy]quinazolin-4(3H)-one
Mycobacterium tuberculosis
pH and temperature not specified in the publication
0.00897 - 0.009
chlorimuron ethyl
0.00177
KHG20612
Mycobacterium tuberculosis
pH and temperature not specified in the publication
0.012 - 0.32
L-isoleucine
0.0014 - 0.0016
L-leucine
0.004 - 0.012
L-valine
0.00064 - 0.021
Londax
0.00596
methyl-2-[(4-methoxy-6-methyl-1,3,5-triazin-2-yl)carbamoylsulfamoyl]benzoate
Mycobacterium tuberculosis
pH and temperature not specified in the publication
0.00596 - 0.006
metsulfuron methyl
0.00177
N-phenyl-3-(phenyldisulfanyl)-1H-1,2,4-triazole-1-carboxamide
Mycobacterium tuberculosis
pH and temperature not specified in the publication
0.011 - 0.048
NC-311
0.0042
primisulfuron methyl
Mycobacterium tuberculosis
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IC50: 0.0042 mM, over 80% inhibition at 0.04 mM
0.000087 - 0.00087
pyrazosulfuron ethyl
0.00479 - 0.0048
sulfometuron methyl
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
0.0023
pH 7.5, 37C, purified recombinant His6-tagged mutant E85A
0.034
pH 7.5, 37C, purified recombinant His6-tagged mutant E85Q
0.04
pH 7.5, 37C, purified recombinant His6-tagged mutant H84A
0.063
pH 7.5, 37C, purified recombinant His6-tagged mutant E85D
0.17
isolated catalytic subunit, pH 7.5, 37C
0.19
pH 7.5, 37C, purified recombinant His6-tagged mutant H84T
0.22
pH 7.5, 37C, purified recombinant His6-tagged mutant Q86A
11
presence of 20 mM acetate, pH 7.5, 37C
36
presence of 20 mM acetate, pH 7.5, 37C
4.6
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purified holoenzyme
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
6 - 8
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catalytic subunit
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
catalytic subunit ilvX
UniProt
Manually annotated by BRENDA team
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
evolution
three types of isozymes, AHAS I, II, III, are found in Enterobacteria encoded by ilvBN, ilvGMEDA, ilvIH operons, respectively. Bacterial AHAS consists of a regulatory and a catalytic subunit
malfunction
metabolism
additional information
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
20000
x * 20000, SDS-PAGE
20400
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x * 68300, recombinant His-tagged catalytic subunit, + x * 20400, recombinant His-tagged regulatory subunit, SDS-PAGE
300000
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above, recombinant holoenzyme, gel filtration
68000
68300
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x * 68300, recombinant His-tagged catalytic subunit, + x * 20400, recombinant His-tagged regulatory subunit, SDS-PAGE
SUBUNIT
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
oligomer
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x * 68300, recombinant His-tagged catalytic subunit, + x * 20400, recombinant His-tagged regulatory subunit, SDS-PAGE
tetramer
the enzyme consists of a large catalytic and a small regulatory subunit, two copies of which form the enzyme tetramer The catalytic subunit has a molecular weight of 60-70 kD, the regulator of 10-45 kD
additional information
PROTEIN VARIANTS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
E85A
site-directed mutagenesis, the mutation leads to severe drop in catalyticactivity with reduced affinity toward thiamine diphosphate, , the enzyme shows reduced activity compared to the wild-type enzyme; the mutation leads to severe drop in catalytic activity (0.08% of wild type activity) with reduced affinity toward thiamine diphosphate; the mutation leads to severe drop in catalytic activity with reduced affinity toward thiamine diphosphate
E85D
site-directed mutagenesis, the mutation leads to severe drop in catalyticactivity with reduced affinity toward thiamine diphosphate; the mutation leads to severe drop in catalytic activity (2.23% of wild type activity) with reduced affinity toward thiamine diphosphate
E85Q
site-directed mutagenesis, the mutation leads to severe drop in catalyticactivity with reduced affinity toward thiamine diphosphate; the mutation leads to severe drop in catalytic activity (1.2% of wild type activity) with reduced affinity toward thiamine diphosphate
F147A
4fold decrease in vmax value, strong resistance to sulfonylurea inhibitors
F147R
2.5fold decrease in vmax value, strong resistance to sulfonylurea inhibitors
H84A
site-directed mutagenesis, the mutation leads to the loss of many hydrogen bonds among residues His84, Glu85, and Gln86 in wild-type enzyme; the mutation leads to severe drop in catalytic activity with reduced affinity toward thiamine diphosphate
H84T
site-directed mutagenesis, the enzyme shows reduced activity compared to the wild-type enzyme; the mutation leads to severe drop in catalytic activity with reduced affinity toward thiamine diphosphate
L141A
5fold decrease in vmax value
P126A
site-directed mutagenesis, the mutant exhibits similar kinetics but significantly lower activity compared to the wild-type enzyme
P126A,
the mutant exhibits significantly lower activity than the wild type enzyme
P126E
P126T
P126V
Q86A
site-directed mutagenesis, the enzyme shows reduced activity compared to the wild-type enzyme; the mutation leads to severe drop in catalytic activity with reduced affinity toward thiamine diphosphate
Q86W
site-directed mutagenesis, inactive mutant; the mutation completely abolishes the enzyme's activity
W561R
30fold decrease in vmax value, strong resistance to sulfonylurea inhibitors
PURIFICATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
recombinant His-tagged catalytic subunit to homogeneity
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recombinant His-tagged enzyme subunits from Escherichia coli to homogeneity by nickel affinity chromatography and dialysis
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recombinant N-terminally His6-tagged wild-type and mutant enzymes from Escherichia coli strain BL21(DE3) by nickel affinity chromatography
recombinant soluble His-tagged enzyme mutants from Escherichia coli strain BL21(DE3) to near homogeneity by nickel affinity chromatography, gel filtration, and anion exchange chromatography
CLONED (Commentary)
ORGANISM
UNIPROT
LITERATURE
expression in Escherichia coli
expressed in Escherichia coli BL21(DE3) cells
expressed in Escherichia coli BL21(DE3) cells; recombinant expression of the wild-type enzyme's catalytic subunit, recombinant expression of N-terminally His6-tagged wild-type and mutant enzymes in Escherichia coli strain BL21(DE3)
expression in Escherichia coli
expression of the His-tagged catalytic subunit
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inducible overexpression of the His-tagged enzyme subunits in Escherichia coli strain BL21(DE3)
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sequence comparisoons, recombinant expression of soluble His-tagged enzyme mutants in Escherichia coli strain BL21(DE3)
EXPRESSION
ORGANISM
UNIPROT
LITERATURE
expression level is 0.6 relative to sigA mRNA. Genome sequence of Mycobacterium tuberculosis reveals four genes encoding catalytic subunits, and one regulatory subunit, ilvN. All these genes are expressed in Mycobacterium tuberculosis growing in vitro
expression is upregulated in extended stationary phase, ex vivo, and in acid stress and hypoxic environments
expression level is 0.16 relative to sigA mRNA. Genome sequence of Mycobacterium tuberculosis reveals four genes encoding catalytic subunits, and one regulatory subunit, ilvN. All these genes are expressed in Mycobacterium tuberculosis growing in vitro
expression level is 0.53 relative to sigA mRNA. Genome sequence of Mycobacterium tuberculosis reveals four genes encoding catalytic subunits, and one regulatory subunit, ilvN. All these genes are expressed in Mycobacterium tuberculosis growing in culture
expression level is 0.63 relative to sigA mRNA. Genome sequence of Mycobacterium tuberculosis reveals four genes encoding catalytic subunits, and one regulatory subunit, ilvN. All these genes are expressed in Mycobacterium tuberculosis growing in vitro
APPLICATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
drug development
pharmacology
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AHAS might be a target protein for the development of anti-tuberculosis therapeutics
REF.
AUTHORS
TITLE
JOURNAL
VOL.
PAGES
YEAR
ORGANISM (UNIPROT)
PUBMED ID
SOURCE
Choi, K.; Noh, K.M.; Choi, J.; Park, J.; Won, H.; Kim, J.; Kim, J.; Yoon, M.
Sulfonylurea is a non-competitive inhibitor of acetohydroxyacid synthase from Mycobacterium tuberculosis
Bull. Korean Chem. Soc.
27
1697-1700
2006
Mycobacterium tuberculosis, Mycobacterium tuberculosis H37Rv
-
Manually annotated by BRENDA team
Choi, K.J.; Yu, Y.G.; Hahn, H.G.; Choi, J.D.; Yoon, M.Y.
Characterization of acetohydroxyacid synthase from Mycobacterium tuberculosis and the identification of its new inhibitor from the screening of a chemical library
FEBS Lett.
579
4903-4910
2005
Mycobacterium tuberculosis, Mycobacterium tuberculosis H37Rv
Manually annotated by BRENDA team
Sohn, H.; Lee, K.S.; Ko, Y.K.; Ryu, J.W.; Woo, J.C.; Koo, D.W.; Shin, S.J.; Ahn, S.J.; Shin, A.R.; Song, C.H.; Jo, E.K.; Park, J.K.; Kim, H.J.
In vitro and ex vivo activity of new derivatives of acetohydroxyacid synthase inhibitors against Mycobacterium tuberculosis and non-tuberculous mycobacteria
Int. J. Antimicrob. Agents
31
567-571
2008
Mycobacterium avium, Mycobacterium kansasii, Mycobacterium tuberculosis, Mycobacteroides abscessus
Manually annotated by BRENDA team
Choi, J.; Gedi, V.; Pham, C.; Ryu, K.; Lee, H.; Kim, G.; Yoon, M.
Site-directed mutagenesis of catalytic and regulatory subunits of Mycobacterium tuberculosis acetohydroxyacid synthase
Enzyme Microb. Technol.
46
304-308
2010
Mycobacterium tuberculosis, Mycobacterium tuberculosis (P9WG41), Mycobacterium tuberculosis H37Rv (P9WG41)
-
Manually annotated by BRENDA team
Singh, V.; Chandra, D.; Srivastava, B.S.; Srivastava, R.
Biochemical and transcription analysis of acetohydroxyacid synthase isoforms in Mycobacterium tuberculosis identifies these enzymes as potential targets for drug development
Microbiology
157
29-37
2011
Mycobacterium tuberculosis, Mycobacterium tuberculosis (O06335), Mycobacterium tuberculosis (O53554), Mycobacterium tuberculosis (P9WG39), Mycobacterium tuberculosis (P9WG41), Mycobacterium tuberculosis H37Rv (P9WG39), Mycobacterium tuberculosis H37Rv (P9WG41)
Manually annotated by BRENDA team
Gokhale, K.; Tilak, B.
Mechanisms of bacterial acetohydroxyacid synthase (AHAS) and specific inhibitors of Mycobacterium tuberculosis AHAS as potential drug candidates against tuberculosis
Curr. Drug Targets
16
689-699
2015
Escherichia coli (P00892 and P0ADG1), Escherichia coli (P00893 and P00894), Escherichia coli (P08142 and P0ADF8), Mycobacterium tuberculosis, Mycobacterium tuberculosis (P9WG41 and P9WKJ3), Mycobacterium tuberculosis H37Rv (P9WG41 and P9WKJ3), Pseudomonas aeruginosa, Saccharomyces cerevisiae, Salmonella enterica subsp. enterica serovar Typhimurium
Manually annotated by BRENDA team
Baig, I.A.; Gedi, V.; Lee, S.C.; Koh, S.H.; Yoon, M.Y.
Role of a highly conserved proline-126 in ThDP binding of Mycobacterium tuberculosis acetohydroxyacid synthase
Enzyme Microb. Technol.
53
243-249
2013
Mycobacterium tuberculosis, Mycobacterium tuberculosis (P9WG39), Mycobacterium tuberculosis H37Rv, Mycobacterium tuberculosis H37Rv (P9WG39)
Manually annotated by BRENDA team
Baig, I.A.; Moon, J.Y.; Kim, M.S.; Koo, B.S.; Yoon, M.Y.
Structural and functional significance of the highly-conserved residues in Mycobacterium tuberculosis acetohydroxyacid synthase
Enzyme Microb. Technol.
58-59
52-59
2014
Mycobacterium tuberculosis (P9WG41), Mycobacterium tuberculosis H37Rv (P9WG41)
Manually annotated by BRENDA team
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