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Information on EC 2.3.3.16 - citrate synthase (unknown stereospecificity) and Organism(s) Thermoplasma acidophilum and UniProt Accession P21553
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2.3.3.16 citrate synthase (unknown stereospecificity)IUBMB Comments
This entry has been included to accommodate those citrate synthases for which the stereospecificity with respect to C-2 of oxaloacetate has not been established [cf. EC 2.3.3.1, citrate (Si)-synthase and EC 2.3.3.3, citrate (Re)-synthase].
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The taxonomic range for the selected organisms is: Thermoplasma acidophilum
The expected taxonomic range for this enzyme is: Bacteria, Archaea, Eukaryota
The expected taxonomic range for this enzyme is: Bacteria, Archaea, Eukaryota
Synonyms
citrate synthetase, mitochondrial citrate synthase, peroxisomal citrate synthase, si-citrate synthase, type ii citrate synthase, citrate synthase cit1, bifunctional citrate synthase/2-methylcitrate synthase, citrate condensing enzyme, 
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topSYNONYM 
ORGANISM
UNIPROT
COMMENTARY 
LITERATURE
citrate condensing enzyme
-
-
-
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citrate oxaloacetate-lyase (CoA-acetylating)
-
-
-
-
citrate oxaloacetate-lyase, CoA-acetylating
-
-
-
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citrate synthase
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-
-
-
citrate synthetase
-
-
-
-
citric synthase
-
-
-
-
citric-condensing enzyme
-
-
-
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citrogenase
-
-
-
-
oxalacetic transacetase
-
-
-
-
oxaloacetate transacetase
-
-
-
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synthase, citrate
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-
-
-
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT
LITERATURE
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
PATHWAY SOURCE
PATHWAYS
-
-, -, -, -, -, -, -, -, -, -, -, -, -
SYSTEMATIC NAME
IUBMB Comments
acetyl-CoA:oxaloacetate C-acetyltransferase (thioester-hydrolysing)
This entry has been included to accommodate those citrate synthases for which the stereospecificity with respect to C-2 of oxaloacetate has not been established [cf. EC 2.3.3.1, citrate (Si)-synthase and EC 2.3.3.3, citrate (Re)-synthase].
CAS REGISTRY NUMBER
COMMENTARY
9027-96-7
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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
acetyl-CoA + oxaloacetate + H2O
citrate + CoA
-
condensation step nearly irreversible, reversibility is increased at 70°C
-
r
NATURAL SUBSTRATE
NATURAL 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
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
Guanidinium chloride
-
irreversible inactivation of recombinant wild-type at 1.6 M and of recombinant mutant G196V at 0.2 M, at 0.5 M activation of the wild-type
Urea
-
irreversible inactivation of recombinant wild-type at 9.3 M and of recombinant mutant G196V at 5 M, at up to 8 M activation of the wild-type
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
Guanidinium chloride
-
activation of recombinant wild-type 1.6fold at 0.5 M, inactivation at 1.6 M
Urea
-
activation of recombinant wild-type by 35% at up to 8 M, inactivation at 9.3 M
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
0.003
acetyl-CoA
-
pH and temperature not specified in the publication
0.0052
oxaloacetate
-
pH and temperature not specified in the publication
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
0.0001
acetyl-CoA
D317N mutant protein, value is very uncertain
0.0001
oxaloacetate
D317N mutant protein, value is very uncertain
additional information
additional information
-
kcat is stable over pH-range 6.0-8.0
-
additional information
additional information
-
kcat with citrate and CoA
-
Ki VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
65 - 70
-
chimeric mutant containing the large subunit of Pyrcoccus furiosus and the small subunit of Thermoplasma acidophilum
90
-
chimeric mutant containing the large subunit of Thermoplasma acidophilum and the small subunit of Pyrcoccus furiosus
TEMPERATURE RANGE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
pI VALUE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
8.8
8.8
ORGANISM
COMMENTARY
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
additional information
additional information
-
free enzyme forms various binary and ternary complexes with substrates
SUBUNIT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
dimer
additional information
additional information
-
chimeric mutants with exchanged large and small subunits between Thermoplasma acidophilum and Pyrococcus furiosus, the large subunit is responsible for subunit interaction, the small subunit is responsable for catalytic activity
CRYSTALLIZATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
comparison of rigidity in citrate synthases from thermophiles to investigate the relationship between rigidity and thermostability. The increase in rigidity does not detract from the functional flexibility of the active site in all systems once their respective temperature range has been reached. In hyperthermophiles, salt bridges have stabilising roles in the active site, occuring in close proximity to key residues involved in catalysis and binding of the protein
crystal structure analysis of chimeric mutants with exchange of large and small subunits between Thermoplasma acidophilum and Pyrococcus furiosus
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hanging drop vapor diffusion method, using 0.1 M CHES pH 9.5, 12% (w/v) PEG 4000, 1 mM oxaloacetate
-
unliganded form and the enzyme in complex with oxaloacetate. Oxaloacetate is most likely the quencher of tryptophan fluorescence with the oxaloacetate carbonyl as the electron acceptor
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PROTEIN VARIANTS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
D317G
D317 removes the acetyl-CoA methyl proton during catalysis
D317N
D317 removes the acetyl-CoA methyl proton during catalysis
G196V
-
site-directed mutagenesis, mutation interferes with dimerization, improper dimerization or dissociation of the dimer, reduced enzyme activity and conformational stability
S43C
-
site-directed mutagenesis, 5.7fold reduced activity, unaltered Km values for the substrates and unaltered thermostability
W348Y
-
analysis of tryptophan fluorescence, residue responsible for quenching effect
additional information
-
construction of chimeric enzyme mutants with mix of the large and small subunits of Thermoplasma acidophilum and Pyrococcus furiosus, functional analysis of the subunits
TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
80
additional information
80
-
t1/2 of recombinant wild-type is 10 min, t1/2 of recombinant mutant G196V is 8 min, inactivation of the mutant occurs in 2 stages: a first slow and a second rapid one
additional information
-
thermostability of wild-type and chimeric mutants
PURIFICATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
native and recombinant wild-type, the latter from E. coli and recombinant S43C mutant enzyme from E. coli
-
Ni2+-loaded iminodiacetic acid Sepharose column chromatography and Sephadex 200 gel filtration
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CLONED (Commentary)
ORGANISM
UNIPROT
LITERATURE
expression of chimeric mutant in Escherichia coli citrate synthase deficient strain MOB154
-
REF.
AUTHORS
TITLE
JOURNAL
VOL.
PAGES
YEAR
ORGANISM (UNIPROT)
PUBMED ID
SOURCE
Danson, M.J.; Black, S.C.; Woodland, D.L.; Wood, P.A.
Citric acid cycle enzymes of the archaebacteria: citrate synthase and succinate thiokinase
FEBS Lett.
179
120-124
1985
Haloarcula vallismortis, Halobacterium salinarum, Haloferax volcanii, Methanosarcina barkeri, Natronobacterium gregoryi, Natronococcus occultus, Natronomonas pharaonis, Sulfolobus acidocaldarius, Thermoplasma acidophilum
-
Grossebuter, W.; Goerisch, H.
Partial purification and properties of citrate synthase from the thermoacidophilic archaebacteria Thermoplasma acidophilum and Sulfolobus acidocaldarius
Syst. Appl. Microbiol.
6
119-124
1985
Sulfolobus acidocaldarius, Thermoplasma acidophilum, Sulfolobus acidocaldarius 98-3 / DSM 639, Thermoplasma acidophilum 122-1B3 / ATCC 27658
-
Smith, L.D.; Stevenson, K.J.; Hough, D.W.; Danson, M.J.
Citrate synthase from the thermophilic archaebacteria Thermoplasma acidophilum and Sulfolobus acidocaldarius
FEBS Lett.
225
277-281
1987
Sulfolobus acidocaldarius, Thermoplasma acidophilum, Sulfolobus acidocaldarius 98-3 / DSM 639
-
Kocabryik, S.; Erduran, I.; Russell, R.J.M.; Danson, M.J.; Hough, D.W.
The effect of C43 mutation on thermostability and kinetic properties of citrate synthase from Thermoplasma acidophilum
Biochem. Biophys. Res. Commun.
224
224-228
1996
Thermoplasma acidophilum
Kocabiyik, S.; Erduran, I.
The effect of valine substitution for glycine in the dimer interface of citrate synthase from Thermoplasma acidophilum on stability and activity
Biochem. Biophys. Res. Commun.
275
460-465
2000
Thermoplasma acidophilum
Arnott, M.A.; Michael, R.A.; Thompson, C.R.; Hough, D.W.; Danson, M.J.
Thermostability and thermoactivity of citrate synthases from the thermophilic and hyperthermophilic archaea, Thermoplasma acidophilum and Pyrococcus furiosus
J. Mol. Biol.
304
657-668
2000
Pyrococcus furiosus, Thermoplasma acidophilum
Kurz, L.C.; Drysdale, G.; Riley, M.; Tomar, M.A.; Chen, J.; Russell, R.J.M.; Danson, M.J.
Kinetics and mechanism of the citrate synthase from the thermophilic archaeon Thermoplasma acidophilum
Biochemistry
39
2283-2296
2000
Sus scrofa, Thermoplasma acidophilum
Kurz, L.C.; Fite, B.; Jean, J.; Park, J.; Erpelding, T.; Callis, P.
Photophysics of tryptophan fluorescence: link with the catalytic strategy of the citrate synthase from Thermoplasma acidophilum
Biochemistry
44
1394-1413
2005
Thermoplasma acidophilum
Kurz, L.C.; Constantine, C.Z.; Jiang, H.; Kappock, T.J.
The partial substrate dethiaacetyl-coenzyme A mimics all critical carbon acid reactions in the condensation half-reaction catalyzed by Thermoplasma acidophilum citrate synthase
Biochemistry
48
7878-7891
2009
Thermoplasma acidophilum (P21553)
Murphy, J.R.; Donini, S.; Kappock, T.J.
An active site-tail interaction in the structure of hexahistidine-tagged Thermoplasma acidophilum citrate synthase
Acta Crystallogr. Sect. F
71
1292-1299
2015
Thermoplasma acidophilum
McManus, T.J.; Wells, S.A.; Walker, A.B.
Salt bridge impact on global rigidity and thermostability in thermophilic citrate synthase
Phys. Biol.
17
016002
2019
Thermoplasma acidophilum (P21553), Saccharolobus solfataricus (P80148), Thermus thermophilus (Q5SIM6), Thermus thermophilus DSM 579 (Q5SIM6), Saccharolobus solfataricus DSM 1617 (P80148)
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