Information on EC 6.3.4.2 - CTP synthase (glutamine hydrolysing)

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

EC NUMBER
COMMENTARY
6.3.4.2
-
RECOMMENDED NAME
GeneOntology No.
CTP synthase (glutamine hydrolysing)
REACTION
REACTION DIAGRAM
COMMENTARY
ORGANISM
UNIPROT
LITERATURE
ATP + UTP + L-glutamine = ADP + phosphate + CTP + L-glutamate
show the reaction diagram
mechanism proceeds by formation of a phosphorylated pyrimidinone
-
ATP + UTP + L-glutamine = ADP + phosphate + CTP + L-glutamate
show the reaction diagram
mechanism, the initial chemical step catalyzed by CTP synthetase is the phosphorylation of UTP by ATP to form an enzyme-bound intermediate
-
ATP + UTP + L-glutamine = ADP + phosphate + CTP + L-glutamate
show the reaction diagram
overall reaction
-
-
-
ATP + UTP + NH3 = ADP + phosphate + CTP
show the reaction diagram
(1b)
-
-
-
L-glutamine + H2O = L-glutamate + NH3
show the reaction diagram
(1a)
-
-
-
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
amination
-
-
-
-
PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
Metabolic pathways
-
-
Pyrimidine metabolism
-
-
pyrimidine metabolism
-
-
UTP and CTP de novo biosynthesis
-
-
UTP and CTP dephosphorylation I
-
-
UTP and CTP dephosphorylation II
-
-
SYSTEMATIC NAME
IUBMB Comments
UTP:ammonia ligase (ADP-forming)
The enzyme contains three functionally distinct sites: an allosteric GTP-binding site, a glutaminase site where glutamine hydrolysis occurs (cf. EC 3.5.1.2, glutaminase), and the active site where CTP synthesis takes place. The reaction proceeds via phosphorylation of UTP by ATP to give an activated intermediate 4-phosphoryl UTP and ADP [4,5]. Ammonia then reacts with this intermediate generating CTP and a phosphate. The enzyme can also use ammonia from the surrounding solution [3,6].
SYNONYMS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
CTP synthase
-
-
CTP synthase
-
-
CTP synthase
-
-
CTP synthase
-
-
CTP synthetase
-
-
-
-
CTP synthetase
-
-
CTP synthetase
-
-
CTP synthetase
-
-
CTP synthetase 1
-
-
CTPS
-
-
-
-
CTPS
-
-
CTPS2
-
-
CTPS2
Q9NRF8
-
cytidine 5'-triphosphate synthase
-
-
cytidine 5'-triphosphate synthetase
-
-
-
-
cytidine 5'-triphosphate synthetase
-
-
cytidine triphosphate synthetase
-
-
-
-
cytidine triphosphate synthetase
-
-
cytidine triphosphate synthetase 1
-
-
pfCTP synthetase
-
-
synthetase, cytidine triphosphate
-
-
-
-
uridine triphosphate aminase
-
-
-
-
UTP-ammonia ligase
-
-
-
-
UTP:ammonia ligase (ADP-forming)
-
-
CAS REGISTRY NUMBER
COMMENTARY
9023-56-7
-
ORGANISM
COMMENTARY
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
strain L2/CPEC
-
-
Manually annotated by BRENDA team
Chlamydia trachomatis L2/CPEC
strain L2/CPEC
-
-
Manually annotated by BRENDA team
BL21(DE3)
SwissProt
Manually annotated by BRENDA team
strain B
-
-
Manually annotated by BRENDA team
strain HB101 harboring the plasmid pMW5
-
-
Manually annotated by BRENDA team
-
SwissProt
Manually annotated by BRENDA team
CTP synthase 2
SwissProt
Manually annotated by BRENDA team
CTP synthetase type I
GenBank
Manually annotated by BRENDA team
CTP synthetase type II
SwissProt
Manually annotated by BRENDA team
CTP synthetase type II
-
-
Manually annotated by BRENDA team
genes CTPS1 and CTPS2
-
-
Manually annotated by BRENDA team
subsp. cremonis
-
-
Manually annotated by BRENDA team
CTP synthetase type I
SwissProt
Manually annotated by BRENDA team
CTP synthetase type II
SwissProt
Manually annotated by BRENDA team
URA7 and URA8 genes encoding CTP synthetase
-
-
Manually annotated by BRENDA team
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
malfunction
-
mutations disrupting CTP synthase isoform C or isoform A expression results in cytoophidium disassembly
physiological function
-
central role of CTP in the biosynthesis of nucleic acids, phospholipids, and sialic acid
physiological function
-
CTP synthase forms filaments in Caulobacter crescentus, and the filaments it forms regulate the curvature of Caulobacter crescentus cells independently of its catalytic function. The morphogenic role of CTP synthase requires its functional interaction with the intermediate filament, crescentin
physiological function
-
CTP synthase protein molecules form filamentous structures termed cytoophidia or CTP synthase filaments in the cytoplasm and nucleus
SUBSTRATE
PRODUCT                      
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
ATP + dUTP + NH4+
ADP + phosphate + dCTP
show the reaction diagram
-
-
-
?
ATP + dUTP + NH4+
ADP + phosphate + dCTP
show the reaction diagram
-
half-saturating concentration of 0.6 mM for dUTP, it is unlikely that this reaction plays a significant physiological role
-
?
ATP + UTP + CH3NHOH
ADP + phosphate + ?
show the reaction diagram
-
-
-
-
?
ATP + UTP + Gln
ADP + phosphate + CTP + Glu
show the reaction diagram
-
-
-
-
?
ATP + UTP + Gln
ADP + phosphate + CTP + Glu
show the reaction diagram
-
-
-
-
?
ATP + UTP + Gln + H2O
ADP + CTP + Glu + phosphate
show the reaction diagram
P0A7E5
-
-
-
?
ATP + UTP + Gln + H2O
ADP + CTP + Glu + phosphate
show the reaction diagram
-
-
-
-
?
ATP + UTP + Gln + H2O
ADP + CTP + Glu + phosphate
show the reaction diagram
-
-
-
-
?
ATP + UTP + Gln + H2O
ADP + CTP + Glu + phosphate
show the reaction diagram
Q9NRF8
-
-
-
?
ATP + UTP + Gln + H2O
ADP + CTP + Glu + phosphate
show the reaction diagram
-
-
-
-
?
ATP + UTP + Gln + H2O
ADP + CTP + Glu + phosphate
show the reaction diagram
-
-
-
-
?
ATP + UTP + Gln-NH2
ADP + phosphate + CTP + N4-amino CTP
show the reaction diagram
-
-
-
-
?
ATP + UTP + Gln-OH
ADP + phosphate + CTP + N4-hydroxy-CTP
show the reaction diagram
-
-
-
-
?
ATP + UTP + glutamine
ADP + phosphate + CTP + Glu
show the reaction diagram
-
-
-
-
?
ATP + UTP + glutamine
ADP + phosphate + CTP + Glu
show the reaction diagram
-
-
-
?
ATP + UTP + glutamine
ADP + phosphate + CTP + Glu
show the reaction diagram
-
-
-
?
ATP + UTP + glutamine
ADP + phosphate + CTP + Glu
show the reaction diagram
-
-
-
-
?
ATP + UTP + glutamine
ADP + phosphate + CTP + Glu
show the reaction diagram
-
-
-
-
?
ATP + UTP + glutamine
ADP + phosphate + CTP + Glu
show the reaction diagram
-
-
-
-
?
ATP + UTP + glutamine
ADP + phosphate + CTP + Glu
show the reaction diagram
-
-
-
-
?
ATP + UTP + glutamine
ADP + phosphate + CTP + Glu
show the reaction diagram
-
maximal activity with NH4+ is at least 20% greater than with glutamine
-
-
?
ATP + UTP + glutamine
ADP + phosphate + CTP + L-glutamate
show the reaction diagram
-
-
-
-
?
ATP + UTP + glutamine
ADP + phosphate + CTP + L-glutamate
show the reaction diagram
-
CTP synthetase is a cytosolic-associated glutamine amidotransferase enzyme that catalyzes the ATP-dependent transfer of the amide nitrogen from glutamine to the C-4 position of UTP to form CTP. CTP is an essential precursor of all membrane phospholipids that are synthesized via the Kennedy, i.e. CDP-choline and CDP-ethanolamine branches, and CDP-diacylglycerol pathways. The URA7-encoded CTP synthetase is responsible for the majority of the CTP made in vivo. Regulation mechanisms, detailed overview
-
-
?
ATP + UTP + glutamine
ADP + phosphate + CTP + L-glutamate
show the reaction diagram
-
the CTPS1-encoded enzyme is regulated by reversible phosphorylation at Thr455, regulation mechanisms, overview
-
-
?
ATP + UTP + hydroxylamine
ADP + phosphate + N4-hydroxyCTP
show the reaction diagram
-
activity is about 3fold higher than activity with NH4+
-
?
ATP + UTP + hydroxylamine
ADP + phosphate + N4-OH-CTP
show the reaction diagram
-
-
-
-
?
ATP + UTP + L-Gln
ADP + phosphate + CTP + L-Glu
show the reaction diagram
Q9NRF8
-
-
-
?
ATP + UTP + L-glutamine
ADP + phosphate + CTP + L-glutamate
show the reaction diagram
-
-
-
-
?
ATP + UTP + L-glutamine
ADP + phosphate + CTP + L-glutamate
show the reaction diagram
-
-
-
-
?
ATP + UTP + L-glutamine
ADP + phosphate + CTP + L-glutamate
show the reaction diagram
-
-
-
-
ir
ATP + UTP + L-glutamine
ADP + phosphate + CTP + L-glutamate
show the reaction diagram
-
CTPS catalyses the ATP-dependent formation of CTP from UTP using either ammonia or L-glutamine as the nitrogen source
-
-
?
ATP + UTP + NH2NH2
ADP + phosphate + ?
show the reaction diagram
-
-
-
-
?
ATP + UTP + NH2NH2
ADP + phosphate + CTP + N4-amino CTP
show the reaction diagram
-
-
-
-
?
ATP + UTP + NH2OH
ADP + phosphate + N4-hydroxy-CTP
show the reaction diagram
-
-
-
-
?
ATP + UTP + NH3
ADP + CTP + phosphate
show the reaction diagram
P0A7E5
-
-
-
?
ATP + UTP + NH3
ADP + CTP + phosphate
show the reaction diagram
-
-
-
-
?
ATP + UTP + NH3
ADP + phosphate + CTP
show the reaction diagram
-
-
-
-
?
ATP + UTP + NH3
ADP + phosphate + CTP
show the reaction diagram
-
CTPS1 is involved in microtubule network formation and/or stabilzation, overview
-
-
?
ATP + UTP + NH3
ADP + phosphate + CTP
show the reaction diagram
-
CTPS catalyses the ATP-dependent formation of CTP from UTP using either ammonia or L-glutamine as the nitrogen source
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
-
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
ir
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
-
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
P17812, Q9NRF8
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
P70303, P70698
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
P28274, P38627
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
P0A7E5
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
Q5SIA8
last step in CTP biosynthesis
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
Chlamydia trachomatis L2/CPEC
-
-
-
?
ATP + UTP + O-methylhydroxylamine
ADP + phosphate + N4-methoxyCTP
show the reaction diagram
-
-
-
?
deoxyATP + UTP + NH4+
deoxyADP + phosphate + CTP
show the reaction diagram
-
-
-
-
?
deoxyGTP + UTP + NH4+
deoxyGDP + phosphate + CTP
show the reaction diagram
-
-
-
-
?
deoxyGTP + UTP + NH4+
deoxyGDP + phosphate + CTP
show the reaction diagram
-
-
-
-
-
GTP + UTP + NH4+
GDP + phosphate + CTP
show the reaction diagram
-
-
-
-
?
GTP + UTP + NH4+
GDP + phosphate + CTP
show the reaction diagram
-
-
-
-
-
GTP + UTP + NH4+
GDP + phosphate + CTP
show the reaction diagram
-
-
-
-
-
GTP + UTP + NH4+
GDP + phosphate + CTP
show the reaction diagram
-
-
-
-
-
UTP + ATP + NH3
CTP + ADP + phosphate
show the reaction diagram
-
the enzyme is regulated in a complex fashion, overview, NH3 from glutamine deamination or exogenous
-
-
?
GTP + UTP + NH4+
GDP + phosphate + CTP
show the reaction diagram
-
-
-
-
-
additional information
?
-
-
key enzyme for biosynthesis of cytosine ribonucleotides
-
-
-
additional information
?
-
-
the enzyme catalyzes the rate-limiting step in synthesis of cytosine nucleotides from both de novo and uridine-salvage pathways
-
-
-
additional information
?
-
-
rate-limiting enzyme in the synthesis of cytosine nucleotides from both de novo and uridine-salvage pathways. In human lymphoblastic leukemia cells the synthesis of CTP occurs predominantly via CTP synthetase, whereas in proliferating normal human T lymphocytes the salvage of cytidine is preferred
-
-
-
additional information
?
-
-
repression of the pyrG gene encoding cytidine triphosphate synthetase is responsive to cytidine nucleotide levels and is independent of both uridine nucleotides and PyrR-dependent attenuation
-
-
-
additional information
?
-
-
CTP limitation increases expression of CTP synthase in Lactococcus lactis. At normal CTP concentrations a terminator is preferentially formed in the pyrG leader, thereby reducing expression of CTP synthase. At low CTP concentrations the RNA polymerase pauses at a stretch of C residues inthe pyrG leader, thereby allowing an antiterminator to form and transcription to proceed
-
-
-
additional information
?
-
-
in Lactococcus lactis the pyrG gene product is the only enzyme responsible for the amination of UTP to CTP
-
-
-
additional information
?
-
-
the enzyme is one of the key enzymes in pyrimidine nucleotide anabolic pathways. The activity of this enzyme is elevated in various malignancies including acute lymphocytic leukemia
-
-
-
additional information
?
-
P17812, Q9NRF8
CTP synthetase plays a pivotal role in the synthesis of CTP and dCTP
-
-
-
additional information
?
-
P70303, P70698
CTP synthetase plays a pivotal role in the synthesis of CTP and dCTP
-
-
-
additional information
?
-
P28274, P38627
CTP synthetase plays a pivotal role in the synthesis of CTP and dCTP
-
-
-
additional information
?
-
P0A7E5
CTP synthetase plays a pivotal role in the synthesis of CTP and dCTP
-
-
-
additional information
?
-
-
regulation of CTP synthetase activity by CTP plays an important role in the regulation of phospholipid synthesis
-
-
-
additional information
?
-
-
the enzyme is allosterically regulated by CTP product inhibition and by reversible phosphorylation
-
-
-
additional information
?
-
-
CTPS1 interacts with the GST-tagged peptidyl prolyl isomerase Pin1 from Xenopus laevis in a Ser575 phosphorylation-dependent manner, the CTPS1 also binds several other enzyme, e.g. alpha-tubulin, overview
-
-
-
additional information
?
-
-
UTP- and CTP-binding structures, overview
-
-
-
additional information
?
-
-
the enzyme can utilize NH3 as a substrate
-
-
-
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate)
LITERATURE
(Substrate)
COMMENTARY
(Product)
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
ATP + UTP + glutamine
ADP + phosphate + CTP + L-glutamate
show the reaction diagram
-
CTP synthetase is a cytosolic-associated glutamine amidotransferase enzyme that catalyzes the ATP-dependent transfer of the amide nitrogen from glutamine to the C-4 position of UTP to form CTP. CTP is an essential precursor of all membrane phospholipids that are synthesized via the Kennedy, i.e. CDP-choline and CDP-ethanolamine branches, and CDP-diacylglycerol pathways. The URA7-encoded CTP synthetase is responsible for the majority of the CTP made in vivo. Regulation mechanisms, detailed overview
-
-
?
ATP + UTP + glutamine
ADP + phosphate + CTP + L-glutamate
show the reaction diagram
-
the CTPS1-encoded enzyme is regulated by reversible phosphorylation at Thr455, regulation mechanisms, overview
-
-
?
ATP + UTP + L-glutamine
ADP + phosphate + CTP + L-glutamate
show the reaction diagram
-
-
-
-
?
ATP + UTP + L-glutamine
ADP + phosphate + CTP + L-glutamate
show the reaction diagram
-
-
-
-
?
ATP + UTP + L-glutamine
ADP + phosphate + CTP + L-glutamate
show the reaction diagram
-
-
-
-
ir
ATP + UTP + NH3
ADP + phosphate + CTP
show the reaction diagram
-
-
-
-
?
ATP + UTP + NH3
ADP + phosphate + CTP
show the reaction diagram
-
CTPS1 is involved in microtubule network formation and/or stabilzation, overview
-
-
?
UTP + ATP + NH3
CTP + ADP + phosphate
show the reaction diagram
-
the enzyme is regulated in a complex fashion, overview
-
-
?
ATP + UTP + NH4+
ADP + phosphate + CTP
show the reaction diagram
Q5SIA8
last step in CTP biosynthesis
-
-
?
additional information
?
-
-
key enzyme for biosynthesis of cytosine ribonucleotides
-
-
-
additional information
?
-
-
the enzyme catalyzes the rate-limiting step in synthesis of cytosine nucleotides from both de novo and uridine-salvage pathways
-
-
-
additional information
?
-
-
rate-limiting enzyme in the synthesis of cytosine nucleotides from both de novo and uridine-salvage pathways. In human lymphoblastic leukemia cells the synthesis of CTP occurs predominantly via CTP synthetase, whereas in proliferating normal human T lymphocytes the salvage of cytidine is preferred
-
-
-
additional information
?
-
-
repression of the pyrG gene encoding cytidine triphosphate synthetase is responsive to cytidine nucleotide levels and is independent of both uridine nucleotides and PyrR-dependent attenuation
-
-
-
additional information
?
-
-
CTP limitation increases expression of CTP synthase in Lactococcus lactis. At normal CTP concentrations a terminator is preferentially formed in the pyrG leader, thereby reducing expression of CTP synthase. At low CTP concentrations the RNA polymerase pauses at a stretch of C residues inthe pyrG leader, thereby allowing an antiterminator to form and transcription to proceed
-
-
-
additional information
?
-
-
in Lactococcus lactis the pyrG gene product is the only enzyme responsible for the amination of UTP to CTP
-
-
-
additional information
?
-
-
the enzyme is one of the key enzymes in pyrimidine nucleotide anabolic pathways. The activity of this enzyme is elevated in various malignancies including acute lymphocytic leukemia
-
-
-
additional information
?
-
P17812, Q9NRF8
CTP synthetase plays a pivotal role in the synthesis of CTP and dCTP
-
-
-
additional information
?
-
P70303, P70698
CTP synthetase plays a pivotal role in the synthesis of CTP and dCTP
-
-
-
additional information
?
-
P28274, P38627
CTP synthetase plays a pivotal role in the synthesis of CTP and dCTP
-
-
-
additional information
?
-
P0A7E5
CTP synthetase plays a pivotal role in the synthesis of CTP and dCTP
-
-
-
additional information
?
-
-
regulation of CTP synthetase activity by CTP plays an important role in the regulation of phospholipid synthesis
-
-
-
additional information
?
-
-
the enzyme is allosterically regulated by CTP product inhibition and by reversible phosphorylation
-
-
-
COFACTOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
ATP
-
dependent on
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
Co2+
-
stimulates at a lower level than Mg2+
Mg2+
-
required, the activation curve for free Mg2+ concentration is greatly dependent on whether the concentration of ATP and UTP are near saturating
Mg2+
-
dUTP-dependent activity is dependent on Mg2+, maximal activity at 4 mM
Mg2+
-
absolutely dependent on
Mg2+
-
required, no activity in absence of
Mg2+
-
dependent on 4 mM Mg2+ for maximal activity
Mg2+
-
the enzyme requires more Mg2+ for full catalytic activity than required simply to complex the nucleotide substrate. Half-saturation value for Mg2+ is 2.6 mM for the reaction with NH4+ and 2.4 mM for the glutamine-dependent reaction
Mg2+
-
absolute requirement
Mg2+
P0A7E5
assay with 10 mM MgCl2
Mg2+
-
assay with 30 mM MgCl2
Mg2+
-
assay with 10 mM MgCl2
Mg2+
-
; assay with 10 mM MgCl2
Mg2+
-
assay with 10 mM Mg2+
Mn2+
-
stimulates at a lower level than Mg2+
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
1,3,7,9-tetramethyluric
-
-
1,3,7-trimethyluric acid
-
-
1,3-dimethyluric acid
-
pH-dependent inhibition, overview
1,7-dimethyluric acid
-
pH-dependent inhibition, overview
1-methyluric acid
-
-
2',3'-dialdehyde adenosine 5'-triphosphate
P0A7E5
irreversible inhibitor of CTPS
2'-deoxy-GTP
-
no guanosine, kact: 1.5/sec, KA: 0.21 mM, Ki: 0.36 mM; the GTP analogue is capable of inhibiting Gln-dependent CTP formation at over 0.15 mM
2'-deoxy-guanosine
-
-
2,6-diaminopurine riboside
-
-
2-aminopurine riboside
-
-
2-Thiocytidine 5'-triphosphate
-
-
2-thiouridine 5'-triphosphate
-
-
3'-deoxy-guanosine
-
-
3,7-dimethyluric acid
-
-
3-Deazauridine 5'-triphosphate
-
-
4-thiouridine 5'-triphosphate
-
-
6-diazo-5-oxo-L-norleucine
-
reduces the parasite CTP level even further and inhibits trypanosome proliferation in vitro and in Trypanosoma brucei-infected mice
6-diazo-5-oxo-L-norleucine
-
-
6-thio-GTP
-
the GTP analogue is capable of inhibiting Gln-dependent CTP formation at over 0.15 mM
6-Thioguanine
-
-
6-thioguanosine
-
-
6-thioguanosine 5'-triphosphate
-
no guanosine, kact: 8.5/sec, KA: 0.035 mM, Ki: 0.27 mM
7-deazaguanosine
-
-
8-oxoguanosine
-
-
8-oxoguanosine 5'-triphosphate
-
-
acivicin
-
irreversible inhibition by the glutamine analogue acivin. The acivicin inhibition of Trypanosoma brucei CTPS is more pronounced when the enzyme is preincubated with the drug in the presence of nucleotide substrates than in the absence of substrates
acycloguanosine
-
-
acycloguanosine monophosphate
-
-
adenine
-
-
adenosine
-
-
adenosine 5'-[beta,gamma-imido]triphosphate
-
poor inhibitor compared to ATPgammaS
adenylyl-iminodiphosphate
-
competitive with ATP
alpha-amino-3-chloro-4,5-dihydro-5-isoxazoleacetic acid
-
reduces the parasite CTP level even further and inhibits trypanosome proliferation in vitro and in Trypanosoma brucei-infected mice
ATPgammaS
-
-
Caffeine
-
-
Caffeine
-
-
Co2+
-
above 2 mM
CTP
-
IC50: 0.3 mM
CTP
-
product inhibition of wild-type enzyme, mutant E161K is less sensitive to CTP product inhibition
CTP
-
cooperative inhibition
CTP
-
IC50: 0.32 mM
CTP
-
mixed inhibition
CTP
-
IC50 for the native enzyme: 0.12 in presence of 0.5 mM ATP, 0.22 mM in presence of 1 mM ATP. IC50 for the phosphorylated enzyme: 0.21 mM in presence of 0.5 mM ATP, 0.31 mM in presence of 1 mM ATP
CTP
-
allosteric inhibition
CTP
-
feedback inhibitor; IC50: 0.05 mM
CTP
-
IC50: 0.15 mM
CTP
-
the enzyme from T lymphoblast S49 cells is refractory to complete inhibition by CTP
CTP
-
allosteric regulation, product inhibition
CTP
Q9NRF8
;
Cu2+
-
inhibition is not reversed by EDTA, in presence of dithiothreitol inhibition at concentrations below 0.2 mM
cyclopentenyl cytosine
-
the inhibitor has a cytostatic effect on lymphoblasts of children with acute lymphocytic leukemia
cyclopentenyl cytosine
-
a highly specific inhibitor of CTPS1, in vivo inhibition leads to alterations in the cell nuclei and microtubule network, overview
cyclopentylcytosine triphosphate
-
-
D,L-2-amino-4-phosphonobutyrate
-
-
dCTP
-
very weak inhibitor
DELTA1-Pyrroline-5-carboxylate
-
weak
dideoxy-GTP
-
-
DL-DELTA1-pyrroline 5-carboxylate
-
0.125 mM, complete inhibition of ammonium chloride-dependent CTP synthesis
Gln
-
inhibition of hydroxylamine-dependent N4-OH CTP synthesis in presence of GTP
glutamate gamma-semialdehyde
-
potent linear mixed-type inhibitor, competitive with respect to ammonia, no inhibition of the mutant enzyme C379A
GTP
-
inhibition of N4-OH-CTP synthesis
GTP
-
inhibition of glutamine-dependent CTP formation above 0.15 mM, inhibition of glutamine-dependent CTP formation in a concentration-dependent manner
GTP
-
0.1 mM guanosine, kact: 10.3/sec, KA: 0.088 mM, Ki: 0.22 mM; 0.2 mM guanosine, kact: 8.2/sec, KA: 0.078 mM, Ki: 0.12 mM; allosteric effector, structural requirements for activation are stringent, but requirements for inhibition are lax. GTP promotes Gln hydrolysis but inhibits Gln-dependent CTP formation at concentrations of over 0.15 mM; no guanosine, kact: 10.6/sec, KA: 0.081 mM, Ki: 0.28 mM
GTP
-
GTP acts a positive allosteric effector for Gln-dependent CTP formation. However, at concentrations exceeding 0.15 mM, GTP inhibits Gln-dependent CTP formation. Moreover, GTP is an inhibitor of NH3-dependent CTP formation at all concentrations
GTP
-
inhibits glutamine-dependent CTP formation at concentrations above 0.2 mM
guanosine
-
-
guanosine
-
-
guanosine 5'-tetraphosphate
-
; no guanosine, kact: 4/sec, KA: 0.19 mM, Ki: 0.5 mM; the GTP analogue is capable of inhibiting Gln-dependent CTP formation at over 0.15 mM
Inosine
-
-
ITP
-
no guanosine, kact: 5.2/sec, KA: 2.9 mM, Ki: 4.5 mM; the GTP analogue is capable of inhibiting Gln-dependent CTP formation at over 0.15 mM
L-2-pyrrolidone 5-carboxylate
-
weak competitive inhibition of the reaction with ammonia as substrate, no significant inhibition with glutamine as substrate
N-methylguanosine
-
-
NH4Cl
-
substrate inhibition , a significant part of the inhibition can be shown to be due to the increase in ionic strength with increasing substrate concentrations
Ni2+
-
in presence of dithiothreitol inhibition at concentrations below 0.2 mM
O-methylguanosine
-
-
O-methylguanosine 5'-triphosphate
-
no guanosine, kact: 2.8/sec, KA: 0.13 mM, Ki: 0.29 mM
O6-methyl-GTP
-
the GTP analogue is capable of inhibiting Gln-dependent CTP formation at over 0.15 mM
p-chloromercuribenzenesulfonic acid
-
-
paraxanthine
-
pH-dependent inhibition, overview
PCMB
-
0.01 mM, 50% inhibition
pyrrole-2-carboxylate
-
weak competitive inhibition of the reaction with ammonia as substrate, no significant inhibition with glutamine as substrate
S-nitroso-L-cysteine
-
specific irreversible inhibitor,inhibits the activity by 94%
S-nitroso-L-homocysteine
-
specific irreversible inhibitor, inhibits the activity by 90%
Theobromine
-
-
theophylline
-
pH-dependent inhibition, overview
uracil-4-acetic acid
-
-
Uric acid
-
pH-dependent inhibition, overview
Uric acid
-
-
uridine
-
-
UTP
-
competitive with ATP
xanthine
-
; pH-dependent inhibition, overview
Xanthosine
-
-
Zn2+
-
inhibition is reversed by EDTA, in presence of dithiothreitol inhibition at concentrations below 0.2 mM
Mn2+
-
above 2 mM
additional information
-
enzyme loses activity at ionic strengths higher than 0.4 M
-
additional information
-
GTP analogues inhibite NH3-and Gln-dependent CTP-formation, often in a cooperative manner, to a similar extent as they activate it with IC50 values of 0.2-0.5 mM, the inhibition appears to be due solely to the purine base, binding structures and kinetics, overview. Inhibitor structure-activity study, overview
-
additional information
-
incubation of EcCTPS modified by CysNO and HcyNO with 5 mM DTT for 30 min at 37C reveals that 88% and 97%, respectively, of the original activity can be recovered; it is shown that in the presence of 1 mM Gln, S-nitroso-L-cysteine reduces the enzymatic activity by 88% and by 32% in the presence of 10 mM Gln. Similar studies with S-nitroso-L-homocysteine result in reduction of the activity by 43% and 19%, respectively. The results suggest that the substrate Gln competitively protects the active site of EcCTPS from the modification with S-nitroso-L-cysteine and S-nitroso-L-homocysteine.; no inhibition by S-nitrosoglutathione presumably due to its inability to enter the actve site of the enzyme
-
additional information
-
inhibition by xanthine and derivatives, no inhibition by allantoin, an intact purine ring with anionic character favors inhibition. In general, methylation of the purine does not significantly affect inhibition
-
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
2'-deoxy-GTP
-
0 mM guanosine, kact: 1.5/sec, KA: 0.21 mM, Ki: 0.36 mM; the GTP analogue is capable of activating Gln-dependent CTP formation
2-mercaptoethanol
-
required for optimal activity, above 50 mM increase activity to 221%
2-mercaptoethanol
-
stimulates
6-thio-GTP
-
the GTP analogue is capable of activating Gln-dependent CTP formation
6-thioguanosine 5'-triphosphate
-
0 mM guanosine, kact: 8.5/sec, KA: 0.035 mM, Ki: 0.27 mM
dithiothreitol
-
required for optimal activity, above 50 mM increase activity to 223% mM
GDP
-
slight activation
GMP
-
slight activation
GTP
-
required as an allosteric effector to promote glutamine hydrolysis
GTP
-
required as allosteric effector to promote reaction with glutamine as substrate, GTP functions by stabilizing the protein conformation that binds the tetrahedral intermediate(s) formed during glutamine hydrolysis
GTP
-
the binding of GTP to the allosteric site promotes coordination of the phosphorylation of UTP and hydrolysis of glutamine for optimal efficiency in CTP synthesis rather than just acting to increase the rate of glutamine hydrolysis itself
GTP
-
activates glutamine reaction, no activation of ammonia reaction
GTP
-
essential activator when glutamine is the nitrogen source
GTP
-
not essential, but acts as activator on the glutamine reaction, optimal activation at 1 mM
GTP
-
stimulates reaction with ATP, UTP and Gln
GTP
-
activates enzyme-catalyzed glutamine hydrolysis
GTP
-
allosteric activator
GTP
-
0.1 mM guanosine, kact: 10.3/sec, KA: 0.088 mM, Ki: 0.22 mM; 0.2 mM guanosine, kact: 8.2/sec, KA: 0.078 mM, Ki: 0.12 mM; 0 mM guanosine, kact: 10.6/sec, KA: 0.081 mM, Ki: 0.28 mM; allosteric effector, structural requirements for activation are stringent, but requirements for inhibition are lax. GTP promotes Gln hydrolysis but inhibits Gln-dependent CTP formation at concentrations of over 0.15 mM
GTP
-
required, activates
GTP
-
GTP acts a positive allosteric effector for Gln-dependent CTP formation. However, at concentrations exceeding 0.15 mM, GTP inhibits Gln-dependent CTP formation. Moreover, GTP is an inhibitor of NH3-dependent CTP formation at all concentrations
GTP
-
activates glutamine-dependent CTP formation at concentrations below 0.2 mM
guanosine 5'-tetraphosphate
-
0 mM guanosine, kact: 4/sec, KA: 0.19 mM, Ki: 0.5 mM; the GTP analogue is capable of activating Gln-dependent CTP formation
O-methylguanosine 5'-triphosphate
-
0 mM guanosine, kact: 2.8/sec, KA: 0.13 mM, Ki: 0.29 mM
O6-methyl-GTP
-
the GTP analogue is capable of activating Gln-dependent CTP formation
ITP
-
0 mM guanosine, kact: 5.2/sec, KA: 2.9 mM, Ki: 4.5 mM; the GTP analogue is capable of activating Gln-dependent CTP formation
additional information
-
activation potency in descending order: GTP = 6-thio-GTP, ITP = guanosine 5'-tetraphosphate, O6-methyl-GTP, 2'-deoxy-GTP, no activation with guanosine, GMP, GDP, 2',3'-dideoxy-GTP, acycloguanosine, and acycloguanosine monophosphate, indicating that the 5'-triphosphate, 2'-OH, and 3'-OH are required for full activation, binding structures and kinetics, overview
-
additional information
-
binding of the substrates ATP and UTP, or the product CTP, promotes oligomerization of CTPS from inactive dimers to active tetramers, Gly142 is critical for nucleotide-dependent oligomerization of CTPS to active tetramers
-
additional information
-
the URA7-encoded enzyme is phosphorylated by protein kinases A and C at Ser424, and these phosphorylations stimulate CTP synthetase activity and increase cellular CTP levels and the utilization of the Kennedy pathway
-
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
0.002
ATP
-
-
0.054
ATP
-
pH 8.0, 25C, without GTP
0.07
ATP
-
-
0.097
ATP
-
pH 7.2
0.259
Gln
-
30C, pH 8.0
0.354
Gln
-
37C, pH 8.0, wild-type enzyme
0.497
Gln
-
37C, pH 8.0, mutant enzyme L109A
39.4
Gln-NH2
-
37C, pH 8.0, wild-type enzyme
0.063
Gln-OH
-
37C, pH 8.0, mutant enzyme L109A
0.165
Gln-OH
-
37C, pH 8.0, wild-type enzyme
0.1
glutamine
-
pH 7.4 37C, crude extract
0.196
glutamine
P0A7E5
mutant K306A, presence of 1 mM ATP, 1 mM UTP
0.206
glutamine
P0A7E5
wild-type protein, presence of 3 mM ATP, 2 mM UTP
0.345
glutamine
P0A7E5
wild-type protein, presence of 1 mM ATP, 1 mM UTP
0.424
glutamine
P0A7E5
mutant K306A, presence of 3 mM ATP, 2 mM UTP
0.07
GTP
-
-
0.07
GTP
-
-
0.07
GTP
-
-
0.027
L-Gln
Q9NRF8
wild-type, pH 8.1, 37C
0.072
L-Gln
Q9NRF8
mutant S568A, pH 8.1, 37C
0.1
L-Gln
Q9NRF8
wild-type, pH 8.1, 37C
75.3
NH2OH
-
37C, pH 8.0, mutant enzyme L109A
82.8
NH2OH
-
37C, pH 8.0, wild-type enzyme
0.627
NH3
P0A7E5
mutant K306A, presence of 1 mM ATP, 1 mM UTP
1.47
NH3
P0A7E5
mutant K306A, presence of 3 mM ATP, 2 mM UTP
1.54
NH3
P0A7E5
mutant K297A, presence of 1 mM ATP, 1 mM UTP
2.15
NH3
-
37C, pH 8.0, wild-type enzyme
2.15
NH3
P0A7E5
wild-type protein, presence of 1 mM ATP, 1 mM UTP
2.17
NH3
-
37C, pH 8.0, mutant enzyme L109A
2.79
NH3
P0A7E5
wild-type protein, presence of 3 mM ATP, 2 mM UTP
54
NH4+
-
30C, pH 8.0, wild-type enzyme
56
NH4+
-
30C, pH 8.0, mutant enzyme G360A
57
NH4+
-
30C, pH 8.0, mutant enzyme R359M
78
NH4+
-
30C, pH 8.0, mutant enzyme E362Q
92
NH4+
-
30C, pH 8.0, mutant enzyme G360P; 30C, pH 8.0, mutant enzyme R359P
0.027
UTP
-
pH 8.0, 25C, without GTP
0.04
UTP
-
pH 8.0, 30C, phosphorylated enzyme, in presence of 2 mM ATP
0.05
UTP
-
pH 8.0, 30C, native enzyme, in presence of 2 mM ATP
0.07
UTP
-
pH 8.0, mutant enzyme S354A, kinetic constant determined with 0.5 mM ATP
0.07
UTP
-
-
0.071
UTP
-
pH 8.0, 25C, activation with GTP
0.08
UTP
-
pH 8.0, 30C, native enzyme or phosphorylated enzyme, in presence of 0.5 mM ATP
0.1
UTP
-
pH 8.0, mutant enzyme S330A, kinetic constant determined with 0.5 mM ATP
0.16
UTP
-
-
0.19
UTP
Q9NRF8
wild-type, pH 8.1, 37C
0.42
UTP
Q9NRF8
mutant S568A, pH 8.1, 37C
0.59
UTP
Q9NRF8
wild-type, pH 8.1, 37C
0.8
UTP
Q9NRF8
mutant S571A, pH 8.1, 37C
1.9
UTP
Q9NRF8
C-terminal deletion mutant, pH 8.1, 37C
0.26
L-glutamine
-
-
additional information
additional information
-
kinetic mechanism, activation and inhibition kinetics
-
additional information
additional information
-
kinetics of wild-type and mutants
-
additional information
additional information
-
positive cooperativity for ATP and UTP
-
additional information
additional information
Q9NRF8
maximally active at physiological concentrations of ATP, GTP, and glutamine, whereas the Km and IC50 values for the substrate UTP and the product CTP, respectively, are close to their physiological concentrations; maximally active at physiological concentrations of ATP, GTP, and glutamine, whereas the Km and IC50 values for the substrate UTP and the product CTP, respectively, are close to their physiological concentrations
-
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
0.0058
2',3'-dialdehyde adenosine 5'-triphosphate
P0A7E5
K306A: replacement of lysine 306 by alanine reduces the rate of 2',3'-dialdehyde adenosine 5'-triphosphate-dependent inactivation
0.054
2',3'-dialdehyde adenosine 5'-triphosphate
P0A7E5
in the presence of 10 mM UTP
1.5
2'-deoxy-GTP
-
no guanosine
8.5
6-thioguanosine 5'-triphosphate
-
no guanosine, kact: 8.5/sec, KA: 0.035 mM, Ki: 0.27 mM
6.26
ATP
P0A7E5
K306A, presence of 2 mM UTP
10.8
ATP
P0A7E5
K297A, presence of 2 mM UTP
12.8
ATP
P0A7E5
wild-type protein, presence of 2 mM UTP
1.03
Gln
-
pH 8.0, mutant enzyme L109F
1.49
Gln
-
30C, pH 8.0
1.53
Gln
-
pH 8.0, mutant enzyme R105A
1.64
Gln
-
pH 8.0, mutant enzyme L109A
1.86
Gln
-
37C, pH 8.0, mutant enzyme L109A
2.17
Gln
-
pH 8.0, mutant enzyme G110A
3.5
Gln
-
pH 8.0, mutant enzyme D107A
4.22
Gln
-
pH 8.0, mutant enzyme K102A
6.1
Gln
-
pH 8.0, wild-type enzyme
6.1
Gln
-
37C, pH 8.0, wild-type enzyme
1.41
Gln-NH2
-
37C, pH 8.0, wild-type enzyme
0.063
Gln-OH
-
37C, pH 8.0, mutant enzyme L109A
0.453
Gln-OH
-
37C, pH 8.0, wild-type enzyme
0.233
glutamine
-
reaction without GTP
1.28
glutamine
P0A7E5
mutant K306A, presence of 1 mM ATP, 1 mM UTP
1.35
glutamine
P0A7E5
mutant K306A, presence of 3 mM ATP, 2 mM UTP
1.5
glutamine
P0A7E5
wild-type protein, presence of 3 mM ATP, 2 mM UTP
6.1
glutamine
P0A7E5
wild-type protein, presence of 1 mM ATP, 1 mM UTP
6.7
glutamine
-
pH 8.0, wild-type enzyme
8.1
glutamine
-
pH 8.0, recombinant His6-tagged enzyme
8.2
GTP
-
0.2 mM guanosine
10.3
GTP
-
0.1 mM guanosine
10.6
GTP
-
no guanosine
4
guanosine 5'-tetraphosphate
-
no guanosine
14
NH2OH
-
37C, pH 8.0, wild-type enzyme
14.1
NH2OH
-
37C, pH 8.0, mutant enzyme L109A
0.031 - 0.51
NH3
P0A7E5
mutant K306A, presence of 3 mM ATP, 2 mM UTP
0.18
NH3
-
pH 8.0, mutant enzyme H118A
0.92
NH3
-
pH 8.0, mutant enzyme E103A
1.96
NH3
-
pH 8.0, mutant enzymeR104A
2.19
NH3
P0A7E5
mutant K306A, presence of 1 mM ATP, 1 mM UTP
2.25
NH3
-
reaction with or without GTP
4.18
NH3
-
pH 8.0, mutant enzyme G110A
7.59
NH3
P0A7E5
mutant K306A, presence of 3 mM ATP, 2 mM UTP
7.97
NH3
-
pH 8.0, mutant enzyme L109A
8.59
NH3
P0A7E5
mutant K297A, presence of 1 mM ATP, 1 mM UTP
8.7
NH3
-
pH 8.0, mutant enzyme D107A
8.88
NH3
-
pH 8.0, mutant enzyme R105A
9.4
NH3
-
pH 8.0, wild-type enzyme
9.5
NH3
-
37C, pH 8.0, wild-type enzyme
9.5
NH3
P0A7E5
wild-type protein, presence of 1 mM ATP, 1 mM UTP
9.9
NH3
-
pH 8.0, mutant enzyme C379A
10.1
NH3
-
37C, pH 8.0, mutant enzyme L109A
10.4
NH3
-
pH 8.0, mutant enzyme C379S
11
NH3
-
pH 8.0, mutant enzyme L109F
11.3
NH3
P0A7E5
wild-type protein, presence of 3 mM ATP, 2 mM UTP
12.2
NH3
-
pH 8.0, mutant enzyme K102A
1.8
NH4+
-
30C, pH 8.0, mutant enzyme G360P
5.1
NH4+
-
30C, pH 8.0, mutant enzyme R359P
6.3
NH4+
-
30C, pH 8.0, wild-type enzyme
6.9
NH4+
-
30C, pH 8.0, mutant enzyme R359M
7.5
NH4+
-
30C, pH 8.0, mutant enzyme G360A
10.1
NH4+
-
30C, pH 8.0, mutant enzyme E362Q
2.8
O-methylguanosine 5'-triphosphate
-
no guanosine
0.08
UTP
-
pH 8.0, 37C, mutant G142A with L-glutamine, in presence of 0.25 mM GTP
0.67
UTP
-
pH 8.0, 37C, mutant G143A with L-glutamine, in presence of 0.25 mM GTP
4.2
UTP
-
pH 8.0, 37C, mutant G146A with L-glutamine, in presence of 0.25 mM GTP
5
UTP
-
pH 8.0, 37C, wild-type enzyme with L-glutamine, in presence of 0.25 mM GTP
6.9
UTP
P0A7E5
K306A, presence of 2 mM ATP
13.7
UTP
P0A7E5
wild-type protein, presence of 3 mM ATP
14
UTP
P0A7E5
K297A, presence of 3 mM ATP
5.2
ITP
-
no guanosine
additional information
additional information
-
-
-
Ki VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
0.33
1-beta-D-ribofuranosyl-2-thiouracil 5'-triphosphate
-
pH 7.2, inhibition of glutamine reaction
3.36
2',3'-dialdehyde adenosine 5'-triphosphate
P0A7E5
in the presence of 10 mM UTP
3.7
2',3'-dialdehyde adenosine 5'-triphosphate
P0A7E5
K306A: replacement of lysine 306 by alanine reduces the rate of 2',3'-dialdehyde adenosine 5'-triphosphate-dependent inactivation
0.36
2'-deoxy-GTP
-
-
0.08
2-Thiocytidine 5'-triphosphate
-
pH 7.2, inhibition of glutamine reaction and ammonia reaction
0.1
2-thiouridine 5'-triphosphate
-
pH 7.2, inhibition of glutamine reaction
0.25
2-thiouridine 5'-triphosphate
-
pH 7.2, inhibition of ammonia reaction
0.18
5-bromoUTP
-
pH 7.2, inhibition of glutamine reaction
0.53
5-bromoUTP
-
pH 7.2, inhibition of ammonia reaction
0.27
6-thioguanosine 5'-triphosphate
-
-
0.0023
acivicin
-
-
1.1
adenylyliminodiphosphate
-
pH 8.6
0.08
CTP
-
pH 7.2, inhibition of glutamine reaction
0.09
CTP
-
pH 7.2, inhibition of ammonia reaction
5.6
D,L-2-amino-4-phosphonobutyrate
-
pH 8.0, reaction with ammonia
0.182
Gln
-
30C, pH 8.0, inhibition of hydroxylamine-dependent N4-OH CTP synthesis in presence of GTP
0.39
glutamate gamma-semialdehyde
-
-
0.12
GTP
-
0.2 mM guanosine
0.22
GTP
-
0.1 mM guanosine
0.28
GTP
-
no guanosine
0.366
GTP
-
30C, pH 8.0, inhibition of N4-OH-CTP synthesis
0.5
guanosine 5'-tetraphosphate
-
-
4.5
ITP
-
-
0.29
O-methylguanosine 5'-triphosphate
-
-
11
pyrrole-2-carboxylate
-
pH 8.0, reaction with ammonia
0.027
S-nitroso-L-cysteine
-
Kinact: 0.48/min
0.51
s4UTP
-
pH 7.2, inhibition of ammonia reaction
12.6
L-2-pyrrolidone-5-carboxylate
-
pH 8.0, reaction with ammonia
additional information
additional information
-
-
-
additional information
additional information
-
-
-
additional information
additional information
-
kinetic mechanism, activation and inhibition kinetics
-
additional information
additional information
-
inhibition kinetics. Multisite inhibition of CTPS-catalyzed NH3-dependent CTP formation by caffeine
-
IC50 VALUE [mM]
INHIBITOR
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
IMAGE
0.079
1,3,7,9-tetramethyluric
-
pH 8.0, Gln-dependent CTP formation
0.121
1,3,7,9-tetramethyluric
-
pH 8.0, NH3-dependent CTP formation
0.067
1,3,7-trimethyluric acid
-
pH 8.0, Gln-dependent CTP formation
0.07
1,3,7-trimethyluric acid
-
pH 8.0, NH3-dependent CTP formation
0.072
1,3-dimethyluric acid
-
pH 8.0, NH3-dependent CTP formation
0.088
1,3-dimethyluric acid
-
pH 8.0, Gln-dependent CTP formation
0.113
1,7-dimethyluric acid
-
pH 8.0, Gln-dependent CTP formation
0.119
1,7-dimethyluric acid
-
pH 8.0, NH3-dependent CTP formation
0.096
1-methyluric acid
-
pH 8.0, NH3-dependent CTP formation
0.101
1-methyluric acid
-
pH 8.0, Gln-dependent CTP formation
0.33
2'-deoxy-GTP
-
IC50 for inhibition of Gln-dependent CTP formation
0.42
2'-deoxy-GTP
-
IC50 for inhibition of NH3-dependent CTP formation
0.33
2'-deoxy-guanosine
-
IC50 for inhibition of Gln-dependent CTP formation
0.45
2'-deoxy-guanosine
-
IC50 for inhibition of NH3-dependent CTP formation
0.11
2,6-diaminopurine riboside
-
IC50 for inhibition of Gln-dependent CTP formation
0.18
2,6-diaminopurine riboside
-
IC50 for inhibition of NH3-dependent CTP formation
0.22
2-aminopurine riboside
-
IC50 for inhibition of Gln-dependent CTP formation
0.26
2-aminopurine riboside
-
IC50 for inhibition of NH3-dependent CTP formation
0.34
3'-deoxy-guanosine
-
IC50 for inhibition of Gln-dependent CTP formation
0.4
3'-deoxy-guanosine
-
IC50 for inhibition of NH3-dependent CTP formation
0.063
3,7-dimethyluric acid
-
pH 8.0, Gln-dependent CTP formation
0.09
3,7-dimethyluric acid
-
pH 8.0, NH3-dependent CTP formation
0.39
6-Thioguanine
-
IC50 for inhibition of Gln-dependent CTP formation
0.61
6-Thioguanine
-
IC50 for inhibition of NH3-dependent CTP formation
0.23
6-thioguanosine
-
IC50 for inhibition of Gln-dependent CTP formation
0.4
6-thioguanosine
-
IC50 for inhibition of NH3-dependent CTP formation
0.08
8-oxoguanosine
-
; IC50 for inhibition of Gln-dependent CTP formation
0.13
8-oxoguanosine
-
IC50 for inhibition of NH3-dependent CTP formation
0.11
8-oxoguanosine 5'-triphosphate
-
IC50 for inhibition of Gln-dependent CTP formation
0.15
8-oxoguanosine 5'-triphosphate
-
IC50 for inhibition of NH3-dependent CTP formation
0.33
acycloguanosine
-
IC50 for inhibition of Gln-dependent CTP formation
0.45
acycloguanosine
-
8.16 mM NH3, IC50 for inhibition of NH3-dependent CTP formation; IC50 for inhibition of NH3-dependent CTP formation
0.47
acycloguanosine
-
5.44 mM NH3, IC50 for inhibition of NH3-dependent CTP formation
0.48
acycloguanosine
-
2.72 mM NH3, IC50 for inhibition of NH3-dependent CTP formation
0.49
acycloguanosine
-
1.36 mM NH3, IC50 for inhibition of NH3-dependent CTP formation
0.31
acycloguanosine monophosphate
-
IC50 for inhibition of Gln-dependent CTP formation
0.41
acycloguanosine monophosphate
-
IC50 for inhibition of NH3-dependent CTP formation
12.9
adenine
-
pH 8.0, NH3-dependent CTP formation
15.8
adenine
-
pH 8.0, Gln-dependent CTP formation
11
adenosine
-
IC50 for inhibition of Gln-dependent CTP formation
12
adenosine
-
IC50 for inhibition of NH3-dependent CTP formation
0.39
Caffeine
-
pH 8.0, Gln-dependent CTP formation
0.48
Caffeine
-
in HEPES buffer (70 mM, pH 7.3), at 37C
0.51
Caffeine
-
pH 8.0, NH3-dependent CTP formation
0.04
CTP
Q9NRF8
wild-type, pH 8.1, 37C
0.042
CTP
Q9NRF8
wild-type, pH 8.1, 37C
0.045
CTP
Q9NRF8
mutant S571A, pH 8.1, 37C
0.05
CTP
-
IC50: 0.05 mM
0.057
CTP
Q9NRF8
C-terminal deletion mutant, pH 8.1, 37C
0.072
CTP
Q9NRF8
mutant S568A, pH 8.1, 37C
0.15
CTP
-
IC50: 0.15 mM
0.21
CTP
-
IC50 for the native enzyme: 0.12 in presence of 0.5 mM ATP, 0.22 mM in presence of 1 mM ATP. IC50 for the phosphorylated enzyme: 0.21 mM in presence of 0.5 mM ATP, 0.31 mM in presence of 1 mM ATP
0.3
CTP
-
IC50: 0.3 mM
0.32
CTP
-
IC50: 0.32 mM
0.29
dideoxy-GTP
-
IC50 for inhibition of Gln-dependent CTP formation
0.41
dideoxy-GTP
-
IC50 for inhibition of NH3-dependent CTP formation
0.29
GDP
-
2.72 mM NH3, IC50 for inhibition of NH3-dependent CTP formation; 5.44 mM NH3, IC50 for inhibition of NH3-dependent CTP formation; IC50 for inhibition of NH3-dependent CTP formation
0.3
GDP
-
1.36 mM NH3, IC50 for inhibition of NH3-dependent CTP formation
0.33
GDP
-
IC50 for inhibition of Gln-dependent CTP formation
0.23
GMP
-
5.44 mM NH3, IC50 for inhibition of NH3-dependent CTP formation
0.25
GMP
-
2.72 mM NH3, IC50 for inhibition of NH3-dependent CTP formation
0.26
GMP
-
IC50 for inhibition of NH3-dependent CTP formation
0.28
GMP
-
1.36 mM NH3, IC50 for inhibition of NH3-dependent CTP formation
0.29
GMP
-
8.16 mM NH3, IC50 for inhibition of NH3-dependent CTP formation
0.33
GMP
-
IC50 for inhibition of Gln-dependent CTP formation
0.29
GTP
-
5.44 mM NH3, IC50 for inhibition of NH3-dependent CTP formation
0.3
GTP
-
2.72 mM NH3, IC50 for inhibition of NH3-dependent CTP formation; 8.16 mM NH3, IC50 for inhibition of NH3-dependent CTP formation; IC50 for inhibition of NH3-dependent CTP formation
0.31
GTP
-
1.36 mM NH3, IC50 for inhibition of NH3-dependent CTP formation
0.46
GTP
-
in HEPES buffer (70 mM, pH 7.3), at 37C
0.22
guanosine
-
5.44 mM NH3, IC50 for inhibition of NH3-dependent CTP formation
0.26
guanosine
-
1.36 mM NH3, IC50 for inhibition of NH3-dependent CTP formation; 2.72 mM NH3, IC50 for inhibition of NH3-dependent CTP formation
0.29
guanosine
-
8.16 mM NH3, IC50 for inhibition of NH3-dependent CTP formation; IC50 for inhibition of NH3-dependent CTP formation
0.3
guanosine
-
0.30 mM Gln, IC50 for inhibition of Gln-dependent CTP formation
0.32
guanosine
-
10 mM Gln, IC50 for inhibition of Gln-dependent CTP formation; 2.5 mM Gln, IC50 for inhibition of Gln-dependent CTP formation; IC50 for inhibition of Gln-dependent CTP formation
0.35
guanosine
-
0.75 mM Gln, IC50 for inhibition of Gln-dependent CTP formation
0.38
guanosine
-
in HEPES buffer (70 mM, pH 7.3), at 37C
0.33
guanosine 5'-tetraphosphate
-
IC50 for inhibition of Gln-dependent CTP formation
0.42
guanosine 5'-tetraphosphate
-
IC50 for inhibition of NH3-dependent CTP formation
3.5
Inosine
-
IC50 for inhibition of NH3-dependent CTP formation
5.2
Inosine
-
IC50 for inhibition of Gln-dependent CTP formation
2.9
ITP
-
8.16 mM NH3, IC50 for inhibition of NH3-dependent CTP formation
3
ITP
-
2.72 mM NH3, IC50 for inhibition of NH3-dependent CTP formation
3.1
ITP
-
5.44 mM NH3, IC50 for inhibition of NH3-dependent CTP formation
3.3
ITP
-
1.36 mM NH3, IC50 for inhibition of NH3-dependent CTP formation
3.7
ITP
-
IC50 for inhibition of NH3-dependent CTP formation
0.17
N-methylguanosine
-
IC50 for inhibition of Gln-dependent CTP formation
0.23
N-methylguanosine
-
IC50 for inhibition of NH3-dependent CTP formation
0.15
O-methylguanosine
-
0.30 mM Gln, IC50 for inhibition of Gln-dependent CTP formation
0.16
O-methylguanosine
-
10 mM Gln, IC50 for inhibition of Gln-dependent CTP formation; 2.5 mM Gln, IC50 for inhibition of Gln-dependent CTP formation; IC50 for inhibition of Gln-dependent CTP formation
0.17
O-methylguanosine
-
0.75 mM Gln, IC50 for inhibition of Gln-dependent CTP formation
0.25
O-methylguanosine
-
IC50 for inhibition of NH3-dependent CTP formation
0.44
paraxanthine
-
pH 8.0, Gln-dependent CTP formation
0.48
paraxanthine
-
pH 8.0, NH3-dependent CTP formation
0.42
Theobromine
-
pH 8.0, Gln-dependent CTP formation
0.58
Theobromine
-
pH 8.0, NH3-dependent CTP formation
0.43
theophylline
-
pH 8.0, Gln-dependent CTP formation
0.55
theophylline
-
pH 8.0, NH3-dependent CTP formation
4.2
Uracil
-
pH 8.0, Gln-dependent CTP formation
4.7
Uracil
-
pH 8.0, NH3-dependent CTP formation
2.6
uracil-4-acetic acid
-
pH 8.0, Gln-dependent CTP formation
3.2
uracil-4-acetic acid
-
pH 8.0, NH3-dependent CTP formation
0.06
Uric acid
-
pH 8.0, Gln-dependent CTP formation
0.087
Uric acid
-
pH 8.0, NH3-dependent CTP formation
0.1
Uric acid
-
in HEPES buffer (70 mM, pH 7.3), at 37C
3.1
uridine
-
pH 8.0, Gln-dependent CTP formation
4.6
uridine
-
pH 8.0, NH3-dependent CTP formation
0.23
xanthine
-
pH 8.0, Gln-dependent CTP formation
0.37
xanthine
-
pH 8.0, NH3-dependent CTP formation
0.22
Xanthosine
-
IC50 for inhibition of Gln-dependent CTP formation
0.29
Xanthosine
-
IC50 for inhibition of NH3-dependent CTP formation
4.1
ITP
-
IC50 for inhibition of Gln-dependent CTP formation
additional information
additional information
-
xanthine and related compounds inhibit CTPS activity with IC50 = 0.16-0.58 mM. The presence of an 8-oxo function enhances the inhibition to IC50 = 0.060-0.121 mM. Raising the pH from 8.0 to 8.5 results in slightly increased inhibition of NH3-dependent CTP formation by the xanthines
-
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
0.00066
-
crude extract of protein
0.0025
-
specific activity of Escherichia coli expressed enzyme, after a 20 min incubation with protein kinase C, the activity of the CTP synthetase was stimulated 95fold
0.06
-
-
0.1119
-
1st Talon eluate
0.2
-
mutant enzyme S354A
0.3
-
mutant enzyme S36A
0.3986
-
TEV-cleaved 2nd Talon flow-through
0.5515
-
concentrated SourceQ flow-through
0.6
-
mutant enzyme S454A
0.66
-
wild-type enzyme
0.83
-
mutant enzyme S330A
additional information
-
fast assay allows the processing of a large number of samples
additional information
-
during the purification, the specific activity of the enzyme preparation increased 836fold and the total yield is 28%
additional information
-
S462A mutation results in 61%-reduced CTP synthetase 1 phosphorylation. The Saccharomyces cerevisiae-expressed and purified S462A mutant enzyme exhibits a 2fold reduction in CTP synthetase 1 activity, whereas the purified T455A mutant enzyme exhibited a 2fold elevation in CTP synthetase 1 activity, implying that that protein kinase C phosphorylation at Ser462 stimulates human CTP synthetase 1 activity, whereas phosphorylation at Thr455 inhibits activity; T455A mutation results in 58%-reduced CTP synthetase 1 phosphorylation. The Saccharomyces cerevisiae-expressed and purified S462A mutant enzyme exhibits a 2fold reduction in CTP synthetase 1 activity, whereas the purified T455A mutant enzyme exhibited a 2fold elevation in CTP synthetase 1 activity, implying that that protein kinase C phosphorylation at Ser462 stimulates human CTP synthetase 1 activity, whereas phosphorylation at Thr455 inhibits activity
additional information
Q9NRF8
low serum is found to decrease CTPS1 activity, and incubation with the glycogen synthase kinase 3 inhibitor indirubin-3-monoxime protects against this decrease in activity. Incubation with an alkaline phosphatase increases CTPS1 activity in a time-dependent manner, demonstrating that phosphorylation inhibits CTPS1 activity
additional information
-
CTP synthetase 1 activity of the T455A mutant enzyme is 2fold higher than the wild type enzyme. T455A mutation causes a 44% decrease in the amount of human CTP synthetase 1 that is phosphorylated in Saccharomyces cerevisiae cells, accompanied by a 2.5fold increase in the cellular concentration of CTP and a 1.5-fold increase in the choline-dependent synthesis of phosphatidylcholine; Thr 455 is identified as a major site of phosphorylation by protein kinase A, phosphorylation at Thr455 results in the inhibition of activity in vitro and in vivo. Data indicate that phosphorylation at Thr455 attenuates the choline-dependent synthesis of phosphatidylcholine when CTP synthetase 1 enzyme is expressed in Saccharomyces cerevisiae
additional information
-
a structure-activity study using a variety of GTP and guanosine analogues reveals that only a few GTP analogues are capable of activating Gln-dependent CTP formation to varying degrees: GTP > 6-thio-GTP > ITP> guanosine 5'-tetraphosphate > O-methyl-GTP > 2'-deoxy-GTP. No activation is observed with guanosine, GMP, GDP, 2',3'-dideoxy-GTP, acycloguanosine, and acycloguanosine monophosphate indicating that the 5'-triphosphate, 2'-OH, and 3'-OH are required for full activation. The 2-NH2 group is important in binding recognition while substituents at the 6-position are important in activation.
additional information
-
-
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
7 - 9
-
broad
7.3
-
assay at
7.5 - 9.3
-
glutamine-dependent activity
8 - 8.5
-
assay at
8
-
wild-type and mutant enzymes S36A, S330A, S354A and S454A
8
-
dUTP-dependent activity
8
-
glutamine-dependent reaction activated by Co2+
8
P0A7E5
assay at
8
-
assay at
8.1
Q9NRF8
assay at
8.6 - 8.9
-
reaction with glutamine
8.6
-
reaction with ammonia
8.7
-
reaction with NH4+, glutamine-dependent reaction activated by Mg2+ or Mn2+
10.3 - 10.4
-
ammonia-dependent activity,maximal activity with NH4+ is at least 20% greater than with glutamine
pH RANGE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
7 - 10
-
ammonia-dependent activity rises linearly from pH 7 to pH 10
7.3 - 9.5
-
pH 7.3: about 35% of maximal activity, pH 9.5: about 40% of maximal activity
7.3
-
assay at
7.5 - 9
-
pH 7.5: about 70% of maximal activity, pH 9.0: about 55% of maximal activity, dUTP-dependent activity
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
37
P0A7E5
assay at
37
-
assay at
37
Q9NRF8
assay at
37
-
assay at
pI VALUE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
5.6 - 5.9
P28274, P38627
-
5.7
P28274, P38627
-
5.9
P17812, Q9NRF8
-
6.1
P70303, P70698
;
6.5
P17812, Q9NRF8
-
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
SOURCE
-
significantly higher activity is detected in leukaemic cells of children suffering from acute lymphocytic leukemia than in lymphocytes of healthy controls
Manually annotated by BRENDA team
-
in the liver tumours of slow and medium growth rate the specific activity of CTP synthetase is increased 1.8fold to 3.6fold that of normal rat livers, the activity increases from 4.6fold to 11.2fold in rapidly growing hepatomas
Manually annotated by BRENDA team
-
highest activity is found in thombocytes, followed by monocytes, lymphocytes, granulocytes and erythrocytes
Manually annotated by BRENDA team
additional information
-
transcribed and translated primarily during the mid and late stages of the Chlamydial growth cycle
Manually annotated by BRENDA team
additional information
-
pfCTP synthetase exists at all stages of intracellular parasite life cycle
Manually annotated by BRENDA team
additional information
-
the URA7 mRNA is 2-fold more abundant than the URA8 transcript
Manually annotated by BRENDA team
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY
GeneOntology No.
LITERATURE
SOURCE
-
filamentary structure present in all major cell types, exhibits a characteristically elongated and serpentine form
Manually annotated by BRENDA team
-
CTP synthase isoform C forms the cytoophidium
Manually annotated by BRENDA team
-
CTP synthase isoform B distributes diffusely in the cytoplasm
Manually annotated by BRENDA team
-
CTP synthase isoform A localizes in the nucleus
Manually annotated by BRENDA team
additional information
-
CTP synthase forms filaments
-
Manually annotated by BRENDA team
additional information
-
CTP synthase forms filaments in Caulobacter crescentus, and the filaments it forms regulate the curvature of Caulobacter crescentus cells independently of its catalytic function. The morphogenic role of CTP synthase requires its functional interaction with the intermediate filament, crescentin
-
Manually annotated by BRENDA team
PDB
SCOP
CATH
ORGANISM
Escherichia coli (strain K12)
Escherichia coli (strain K12)
Sulfolobus solfataricus (strain ATCC 35092 / DSM 1617 / JCM 11322 / P2)
Thermus thermophilus (strain HB8 / ATCC 27634 / DSM 579)
Thermus thermophilus (strain HB8 / ATCC 27634 / DSM 579)
Thermus thermophilus (strain HB8 / ATCC 27634 / DSM 579)
Trypanosoma brucei brucei (strain 927/4 GUTat10.1)
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
60240
-
mass spectroscopy, processed N-terminal Met1
677028
60380
-
mass spectroscopy, unprocessed N-terminal Met1
677028
105000
-
dimer, gel filtration
648989, 648992
118000
-
gel filtration
648987
122000
-
sucrose density gradient centrifugation
648982
128000
-
monomer, gel filtration
648988
138000
-
sucrose density gradient centrifugation in absence of nucleotides
648991
210000
-
tetramer
648989
210000
-
sucrose density gradient centrifugation in presence of nucleotides
648991
234000
-
gel filtration
648977
263000
-
dimer, gel filtration
648988
280000
-
tetramer, gel filtration
648968
SUBUNITS
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
?
-
x * 70000, SDS-PAGE
?
-
x * 70000, SDS-PAGE
?
-
x * 70000, SDS-PAGE
?
-
x * 100000, SDS-PAGE
?
-
x * 56180, calculation from nucleotide sequence
?
P70303, P70698
x * 66710, calculation from nucleotide sequence
?
P28274, P38627
x * 64783, calculation from nucleotide sequence
?
P28274, P38627
x * 64622, calculation from nucleotide sequence
?
P17812, Q9NRF8
x * 66705,calculation from nucleotide sequence
?
P70303, P70698
x * 65514, calculation from nucleotide sequence
?
P17812, Q9NRF8
x * 65678, calculation from nucleotide sequence
dimer
-
2 * 66000, SDS-PAGE
dimer
-
the enzyme is a dimer of 108000 Da, the dimer associates to form a tetramer in the presence of either ATP or UTP
tetramer
-
-
tetramer
-
4 * 50000, SDS-PAGE
tetramer
-
4 * 68000, SDS-PAGE
tetramer
-
UTP and ATP are responsible for the tetramerization and activation of the inactive dimeric form of the enzyme. UTP is absolutely required for the tatramerization of the enzyme when ATP is present at a saturating concentration
tetramer
-
2 * 60000
tetramer
-
4 * 52000, enzyme exists as tetramer in presence of UTP, Mg2+ and ATP
tetramer
-
the enzyme exists as an inactive dimer in the absence of ATP and UTP. In the presence of saturating concentrations of ATP and UTP, the CTP synthetase protein exists as an active tetramer. Increasing concentrations of ATP and UTP cause a dose-dependent conversion of the dimeric species to a tetramer. Tetramerization is dependent on UTP and Mg2+ ions. ATP facilitates the UTP-dependent teramerization of CTP synthetase by a mechanism that involves the ATP-dependent phosphorylation of UTP catalyzed by the enzyme
tetramer
-
conserved Gly142 is critical for tetramerization, overview
dimer
Q980S6
crystallization data and sedimentation-ultracentrifugation experiments
additional information
-
the enzyme can dissociate to an apparently inactive monomer. The dissociation is reversible and the rate of association is slow
additional information
-
CTP synthetase oligomerizes to a tetramer in the presence of its substrates UTP and ATP
additional information
-
binding of the substrates ATP and UTP, or the product CTP, promotes oligomerization of CTPS from inactive dimers to active tetramers, Gly142 is critical for nucleotide-dependent oligomerization of CTPS to active tetramers. Oligomerization of Gly mutant enzymes, overview
POSTTRANSLATIONAL MODIFICATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
phosphoprotein
-
CTP synthetase is phosphorylated by protein kinase C which leads to 95fold higher activity of CTP synthetase 1. Phosphopeptide mapping and phosphoamino acid analyses shows that CTP synthetase 1 is phosphorylated on multiple serine and threonine residues. It is indicated that protein kinase C phosphorylation at Ser462 stimulates human CTP synthetase 1 activity, whereas phosphorylation at Thr455 inhibits activity
phosphoprotein
Q9NRF8
it is shown that Ser-574 and Ser-575 are phosphorylated residues. Mutation of Ser-571 demonstrates that Ser-571 is the major site phosphorylated by glycogen synthase kinase 3 in intact human embryonic kidney 293 cells by glycogen synthase kinase 3 in vitro. Mutation of Ser-575 prevents phosphorylation of Ser-571, suggesting phosphorylation of Ser-575 is necessary for priming the glycogen synthase kinase 3 phosphorylation of Ser-571, stimulation/inhibition of protein kinase A and protein kinase C does not alter the phosphorylation of endogenous human CTPS1 in human embryonic kidney 293 cells. Low serum conditions increased phosphorylation of endogenous CTPS1 and phosphorylation is inhibited by the glycogen synthase kinase 3 (GSK3) inhibitor indirubin-3-monoxime and GSK3beta short interfering RNAs, demonstrating the involvement of glycogen synthase kinase 3 in phosphorylation of endogenous human CTPS1
phosphoprotein
-
the CTPS1-encoded enzyme is phosphorylated by protein kinases A and C at Thr455, and these phosphorylations stimulate CTP synthetase activity and increase cellular CTP levels and the utilization of the Kennedy pathway
phosphoprotein
-
Low serum treatment increases CTPS2 phosphorylation. Ser568 and Ser571 are two major phosphorylation sites, and Ser568 is phosphorylated by casein kinase 1 both in vitro and in vivo. Mutation of S568A but not S571A significantly increases CTPS2 activity. The S568A mutation has a greater effect on the glutamine than ammonia-dependent activity
phosphoprotein
-
phosphorylation of CTP synthetase by protein kinase A results in the stimulation of CTP synthetase activity. The mechanism of stimulation involves an increase in Vmax of the reaction and an increase of the enzyme affinity for ATP
phosphoprotein
-
phosphorylation of the purified native CTP synthetase with protein kinase A and protein kinase C facilitates the nucleotide-dependent tetramerization. Dephosphorylation of native CTP-desynthetase with alkaline phosphatase prevents the nucleotide-dependent tetramerization of the enzyme
phosphoprotein
-
the enzyme is phosphorylated and stimulated by protein kinase C. Phosphorylation of CTP synthetase on Ser36, Ser330, Ser354, and Ser454 regulates the levels of CTP and phosphatidylcholine synthesis
phosphoprotein
-
the URA7-encoded enzyme is phosphorylated at Ser424 by protein kinases A and C, and these phosphorylations stimulate CTP synthetase activity and increase cellular CTP levels and the utilization of the Kennedy pathway
Crystallization/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
2.3 A resolution crystal structure of apoenzyme using Hg-multiwavelength anomalous dispersion phasing, vapor diffusion method, crystals belong to space group P2(1)2(1)2(1), in which each bifunctional monomer contains a dethiobiotin synthetase-like amidoligase N-terminal domain and a type 1 glutamine amidotransferase C-terminal domain
-
crystal structure analysis discloses a homotetrameric structure and each active site is formed by three different subunits. Sulfate ions bound to the active sites indicate the positions of phosphate-binding sites for the substrates ATP and UTP and the feedback inhibitor CTP. Together with earlier structures of bacterial CTPS, the human CTPS structure provides an extended understanding of the structurefunction relationship of CTPS-family members; the protein is crystallized by the hanging-drop method, equilibrating 1 ml protein solution and 1 ml of a solution containing 0.1 M Tris pH 8.8, 1.2 M (NH4)2SO4 and 50 mM malonic acid against 0.5 ml of a well solution containing 0.1 M Tris pH 8.8 and 1.2 M (NH4)2SO4. Crystals with a maximum dimension of 0.03 nm formed in 3 d
-
dimeric form of CTP synthase at 2.5 A resolution. A comparison of the dimeric interface with the intermolecular interfaces in the tetrameric structures of Thermus thermophilus CTP synthase and Escherichia coli CTP synthase shows that the dimeric interfaces are almost identical in the three systems. Residues that are involved in the tetramerization of Sulfolobus solfataricus CTP synthase all have large thermal parameters in the dimeric form and undergo substantial movement upon tetramerization
Q980S6
hanging-drop vapour-diffusion technique
-
crystal structures of Thermus thermophilus HB8 CTP synthetase as a tetramer in its native form, CTP synthetase as complex with 3 SO42- and CTP synthetase as a complex with glutamine. Crystallization at 20 C using vapor-diffusion method. The space group is I222 with cell dimensions of a = 90.4 A, b = 117.1 A and c = 142.3 A
Q5SIA8
pH STABILITY
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
10.3 - 10.4
-
rapid denaturation at
648981
TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
additional information
-
reversible cold lability
648984
GENERAL STABILITY
ORGANISM
UNIPROT
LITERATURE
the enzyme is stable in absence of ATP and UTP
-
the tetramer is very stable even at dilute enzyme concentrations
-
2-mercaptoethanol is required for optimal stabilization of enzyme activity
-
STORAGE STABILITY
ORGANISM
UNIPROT
LITERATURE
-20C, purified enzyme is stable for months
-
4C, enzyme concentration 1-4 mg/ml, 20 mM sodium phosphate buffer, pH 7.2, 2 mM L-glutamine, 1 mM EDTA, 70 mM 2-mercaptoethanol, 20% glycerol, stable for 3 months
-
-20C, stable for several months
-
-20C, 30% glycerol, 100 mM 2-mercaptoethanol, 40% loss of activity after 4 weeks
-
-80C, 30% glycerol, 100 mM 2-mercaptoethanol, 65% of the original activity is retained after 4 weeks
-
4C, 30% glycerol, 100 mM 2-mercaptoethanol, 65% loss of activity after 4 weeks
-
-80C, stable for at least 6 months
-
Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
Ni2+-IDA resin column chromatography
-
enzyme is purified by gel filtration on a HiLoad 26/60 Superdex 200 column. Active fractions are pooled and applied to a Mono Q HR 5/5 column. Final purifications step is performed on a HiLoad 26/60 Superdex 75 column. The isolated EcCTPS is found >90% pure as judged by SDS-PAGE and ESI-MS.
-
recombinant wild-type and mutant enzyme L109A
-
the soluble histidine-tagged CTPS is purified using metal ion affinity chromatography and the histidine tag is subsequently removed using thrombin-catalyzed cleavage
-
His6-tagged human CTP synthetase 1 is purified by loading onto a Ni2+-NTA column
-
His6-tagged wild type and mutant human CTP synthetase 1 enzymes are expressed and purified from yeast cell extracts with Ni2+-NTA resin; His6-tagged wild type human CTP synthetase 1 is expressed and purified from Escherichia coli by Ni2+-NTA chromatography and with PorosHQ-ion-exchange chromatography
-
Ni2+-IDA resin column chromatography
-
protein is purified by using HisTrap HP and Superdex 75 columns
-
Ni2+-IDA resin column chromatography
-
partial
-
wild-type and mutant enzymes S63A, S330A, S254A and S454A
-
by using talon metal affinity resin, a glass Econo-Column and a Sephadex G-50 column. Proteolysis is performed at 23C for 40 min. The protein solution is then loaded again on a Talon resin column but this time the flow-through, containing CTPS without His tag, is collected. Finally the protein is loaded onto a 0.2-ml SourceQ15 medium column.
-
Ni2+-IDA resin column chromatography
-
Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
expression of the mutant enzyme D149E in Escherichia coli
-
expressed in Escherichia coli BL21(DE3) cells
-
cloned in Escherichia coli as a histidine-tagged fusion protein
-
cloned in Escherichia coli BL-21 as an N-terminal 6xHis-tag fusion protein
P0A7E5
overexpression as a hexahistidine-tagged form
-
wild-type and L109A recombinant enzyme are expressed in Escherichia coli BL21(DE3)
-
-
P17812, Q9NRF8
a carboxyl-terminal FLAG sequence is introduced after insertion of human CTPS1 into pCDNA 4 myc/his, expression by transient transfection of human embryonic kidney (HEK) 293 cells
Q9NRF8
cDNA encoding the synthetase domain of human CTPS (isoform 1) is subcloned into the pNIC-Bsa4 vector, the resulting construct codes for a protein with an N-terminal hexahistidine tag with an integrated TEV protease-cleavage site, the entire plasmid is transformed in Escherichia coli BL-21
-
expressed in Escherichia coli BL21(DE3) cells
-
expression of the human type II CTP synthetase gene in the CTP synthetase-deficient mutant Escherichia coli JF618 completely abolishes the need for exogenous cytidine for their survival
-
expression of wild-type and mutant enzymes in HEK-293 cells, co-expression with GST-tagged Xenopus laevis peptidyl prolyl isomerase Pin1
-
functional expression of human CTPS1 and CTPS2 genes that encode CTP synthetase enzymes in enzyme-deficient Saccharomyces cerevisiae ura7D/ura8D double mutant, complementation
-
human CTP synthetase 1 is expressed and purified from a Saccharomyces cerevisiae ura7delta ura8delta double mutant that lacks CTP synthetase activity
-
protein is expressed as a His6-tagged wild type human CTP synthetase 1 fusion protein in Escherichia coli; protein is expressed as a His6-tagged wild type human CTP synthetase 1 fusion protein in Saccharomyces cerevisiae
-
expressed in Escherichia coli BL21(DE3) cells
-
expression in Escherichia coli
-
expression in a ura7ura8 double mutant that lacks CTP synthetase activity
-
genes ura7D and ura8D, DNA and amino acid sequence determination and analysis, expression analysis
-
expressed in Escherichia coli BL21(DE3) cells
-
synthetase-His6-TEV protease site-tagged Trypanosoma brucei CTP synthetase is expressed in BL21(DE3) pLysS bacteria
-
ENGINEERING
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
D149E
-
the single point mutation in the resistant strain L2/CPEC results in loss of CTP feedback inhibition, cells are resistant to the cytotoxic effects of cyclopentenyl cytosine
D149E
Chlamydia trachomatis L2/CPEC
-
the single point mutation in the resistant strain L2/CPEC results in loss of CTP feedback inhibition, cells are resistant to the cytotoxic effects of cyclopentenyl cytosine
-
C379A
-
mutant enzyme is fully active with ammonia but has no glutamine-dependent activity, no inhibition by glutamate gamma-semialdehyde
D107A
-
enzyme exhibits wild-type NH3-dependent activity and affinity for glutamine, but impaired glutamine-dependent CTP formation, affinity of the mutant enzyme for GTP is reduced 2-4fold
E103A
-
mutant enzyme exhibits no glutamine-dependent activity and is only partially active with NH3
G110A
-
affinity of the mutant enzyme for GTP is reduced 2-4fold, enzyme exhibits wild-type NH3-dependent activity and affinity for glutamine, but impaired glutamine-dependent CTP formation
G142A
-
site-directed mutagenesis, inactive mutant with both ammonia and glutamine
G143A
-
site-directed mutagenesis, kcat/Km for ammonia-dependent and glutamine-dependent CTP formation by mutant G143A are reduced by 22fold and 16fold, respectively, compared to the wild-type enzyme. The mutant is able to form active tetramers in the presence of ATP and UTP
G146A
-
site-directed mutagenesis, kcat/Km for ammonia-dependent and glutamine-dependent CTP formation by mutant G143A are reduced by 1.4fold and 1.8fold, respectively, compared to the wild-type enzyme. The mutant is able to form active tetramers in the presence of ATP and UTP
G351A
-
mutation increases lability of the enzyme, mutant enzyme is not overproduced because of apparent instability and proteolytic degradation
G352C
-
mutation increases lability of the enzyme, mutation abolishes the capacity to form the covalent glutaminyl-cysteine379 catalytic intermediate, thus preventing glutamine amide transfer function, mutant enzyme is not overproduced because of apparent instability and proteolytic degradation
G352P
-
mutation increases lability of the enzyme, mutation abolishes the capacity to form the covalent glutaminyl-cysteine379 catalytic intermediate, thus preventing glutamine amide transfer function, mutant enzyme is not overproduced because of apparent instability and proteolytic degradation
H118A
-
mutant enzyme exhibits no glutamine-dependent activity and is only partially active with NH3
K102A
-
mutant enzyme exhibits wild-type activity with respect to NH3 and glutamine
K297A
P0A7E5
replacement of lysine 297 by alanine does not affect NH3-dependent CTP formation, relative to wild-type CTPS, but reduces kcat for the glutaminase activity 78fold
K306A
P0A7E5
replacement of lysine 306 by alanine reduces the rate of 2',3'-dialdehyde adenosine 5'-triphosphate-dependent inactivation (Kinact = 0.0058/sec, Ki = 3.7 mM) and reduces the apparent affinity for CTPS for both ATP and UTP by 2fold. The efficiency of K306A-catalyzed glutamine-dependent CTP formation is also reduced 2fold while near wild type activity is observed when NH3 is the substrate. These findings suggest that Lys 206 is not essential for ATP binding, but does play a role in bringing about the conformational changes that mediate interactions between ATP and UTP sites, and between the ATP-binding site and the glutamine amide transfer domain
L109A
-
enzyme exhibits wild-type NH3-dependent activity and affinity for glutamine, but impaired glutamine-dependent CTP formation, affinity of the mutant enzyme for GTP is reduced 2-4fold
R104A
-
mutant enzyme exhibits no glutamine-dependent activity and is only partially active with NH3
R105A
-
enzyme exhibits wild-type NH3-dependent activity and affinity for glutamine, but impaired glutamine-dependent CTP formation
V349S
-
mutation increases lability of the enzyme
S462A/T455A
-
S462A and T455A mutations result in a decreased CTP synthetase 1 phosphorylation which appear to be much less than of the individual mutant enzymes S462A or T455A
S568A
Q9NRF8
2fold increase in Km value for UTP. Mutation of S568A significantly increases CTPS2 activity. The S568A mutation has a greater effect on the glutamine than ammonia-dependent activity
S571A
Q9NRF8
4fold increase in Km value for UTP
S571I
Q9NRF8
Ser-571 is the major site phosphorylated by glycogen synthase kinase 3 in intact human embryonic kidney 293 cells
S571I/S574A
Q9NRF8
phosphorylation by glycogen synthase kinase 3 does not show altered incorporation of phosphate compared with S571I alone
S571I/S574A/S575A
Q9NRF8
phosphorylation by glycogen synthase kinase 3 shows a slight decrease in the amount of phosphate incorporated into CTPS1 compared with S571I/S575A, suggesting that Ser-574 may serve as a minor secondary site for glycogen synthase kinase 3 phosphorylation
S571I/S575A
Q9NRF8
phosphorylation by glycogen synthase kinase 3 shows slightly elevated amounts of phosphate incorporated into CTPS1 compared with S571I, suggesting that without the ability to phosphorylate Ser-571 or Ser-575 in vitro, glycogen synthase kinase 3 may phosphorylate an alternative site, albeit to a much lesser extent
S574A
Q9NRF8
greatly reduces phosphorylation by glycogen synthase kinase 3
S574A/S575A
Q9NRF8
greatly reduces phosphorylation by glycogen synthase kinase 3
S575A
Q9NRF8
greatly reduces phosphorylation by glycogen synthase kinase 3. Mutation of Ser-575 prevents the phosphorylation of Ser-571, suggesting that phosphorylation of Ser-575 is necessary for priming the glycogen synthase kinase 3 phosphorylation of Ser-571
S575A
-
site-directed mutagenesis the mutant does not interact with peptidyl prolyl isomerase Pin1
T455A
-
T455A mutation causes a 78% decrease in protein kinase A phosphorylation
E362Q
-
turnover number for NH4Cl-dependent GTP synthesis reaction is 1.6fold higher than wild-type value
G360A
-
5fold increase in GTP-dependent activation of uncoupled glutamine hydrolysis compared to wild-type enzyme. Turnover number for NH4Cl-dependent GTP synthesis reaction is 1.2fold higher than wild-type value
G360P
-
mutant enzyme shows no GTP activation of the uncoupled glutaminase reaction, about 4fold lower turnover number for NH4Cl-dependent CTP synthesis reaction than wild-type enzyme
R359M
-
mutant enzyme shows no GTP activation of the uncoupled glutaminase reaction. Turnover number for NH4Cl-dependent GTP synthesis reaction is 1.1fold higher than wild-type value
R359P
-
mutant enzyme shows no GTP activation of the uncoupled glutaminase reaction. Turnover number for NH4Cl-dependent GTP synthesis reaction is 1.2fold lower than wild-type value
S330A
-
CTP synthetase activity in cells bearing the mutant enzyme is elevated, mutation causes an elevation in the Vmax of the reaction. Mutation does not have a major effect on the oligomerization of CTP synthetase
S354A
-
CTP synthetase activity in extracts from cells bearing the mutant enzyme is reduced when compared with cells bearing the wild-type enzyme, decrease in Vmax of the reaction. The amount of inactive dimeric enzyme form is 98% greater compared to wild-type enzyme
S36A
-
CTP synthetase activity in extracts from cells bearing the mutant enzyme is reduced when compared with cells bearing the wild-type enzyme, decrease in Vmax of the reaction. The amount of inactive dimeric enzyme form is 54% greater compared to wild-type enzyme
S454A
-
CTP synthetase activity in extracts from cells bearing the mutant enzyme is reduced when compared with cells bearing the wild-type enzyme. Mutation does not have a major effect on the oligomerization of CTP synthetase
L109A
-
uncoupling of the hydrolysis of gamma-glutamyl hydroxamate and nascent NH2OH production from N4-hydroxy-CTP formation is more pronounced with mutant than with wild-type enzyme
additional information
P0A7E5
it can be suggested that the conformational change associated with binding ATP may be transmitted through the L10-alpha11 structural unit (residues 297-312) and thereby mediate effects on the glutaminase activity of CTPS
additional information
-
Escherichia coli CtpS can replace the enzymatic and morphogenic functions of Caulobacter crescentus CtpS
E579A
Q9NRF8
HEK 293 cells: no effect on phosphorylation of CTPS1 by glycogen synthase kinase 3
additional information
Q9NRF8
deletion of the C-terminal regulatory domain, residues Ser562-Asp591, of CTPS1 greatly increases the Vmax of the enzyme
E161K
-
specific activity of the mutant URA7-encoded and URA8-encoded enzymes are 2fold greater when compared with the wild-type enzymes. The mutant enzymes are less sensitive to CTP product inhibition with inhibitor constants for CTP of 8.4fold- and 5.5fold greater, respectively, than those of their wild-type counterparts. Cells expressing the E161K mutant enzymes on a multicopy plasmid exhibit an increase in resistance to the pyrimidine poison and cancer therapeutic drug cyclopentenylcytosine and accumulate elevated levels of CTP when compared with cells expressing the wild-type enzymes. Cells expressing the E161K mutation in the URA7-encoded CTP synthetase exhibit an 1.5fold increase in the utilization of the Kennedy pathway for phosphatidylcholine synthesis when compared with control cells. Cells bearing the mutation also exhibit an 1.5fold increase in the synthesis of phosphatidylcholine, 1.3fold for phosphatidylethanolamine and 2fold for phosphatidate and a 1.7fold decrease in synthesis of phosphatidylserine. Cells bearing the e161K mutation exhibit an 1.6fold increase in the ratio of total neutral lipids to phospholipids, an 1.4fold increase in triacylglycerol, a 1.7fold increase in free fatty acids, an1.8fold increase in ergosterol ester and a 1.3fold decrease in diacylgylcerol when compared with control cells
additional information
-
the ura7D/ura8D double mutant, that lacks CTP synthetase activity, shows a lethal phenotype, which can be rescued by functional expression of human CTPS1 and CTPS2 genes that encode CTP synthetase enzymes. In an ura8 mutant, CTP levels are 22% lower than in wild-type, whereas the CTP concentration in an ura7 mutant is 64% lower than in wild-type
APPLICATION
ORGANISM
UNIPROT
COMMENTARY
LITERATURE
analysis
-
fast assay allows the processing of a large number of samples
drug development
-
modifying 2-aminopurine or 2-aminopurine riboside may serve as an effective strategy for developing CTPS inhibitors
drug development
-
CTP is a recognized target for the development of anticancer, antiviral, and antiprotozoal agents
drug development
-
structure serves as a basis for structure-based design of anti-proliferative inhibitors
drug development
-
daily injection of acivicin in trypanosome-infected mice suppresses the infection up to one month without any significant loss of weight. Experiments with cultured bloodstream Trypanosoma brucei shows that acivicin is trypanocidal if present at 0.001 nM concentration for at least 4 d. Acivicin may qualify as a drug with desirable properties, i.e. cure within 7 d, according to the current Target Product Profiles of WHO and DNDi
medicine
-
the enzyme is an target for treatment of African sleeping sickness because the trypanosomes, unlike mammalian cells, cannot compensate for the inhibition of CTP synthetase by the salvage of cytidine. The CTP synthetase inhibitors 6-diazo-5-oxo-L-norleucine and alpha-amino-3-chloro-4,5-dihydro-5-isoxazoleacetic acid reduce the parasite CTP level even further and inhibit trypanosome proliferation in vitro and in Trypanosoma brucei-infected mice