Information on EC 6.3.4.16 - carbamoyl-phosphate synthase (ammonia) and Organism(s) Homo sapiens and UniProt Accession P31327

for references in articles please use BRENDA:EC6.3.4.16
Word Map on EC 6.3.4.16
Please wait a moment until all data is loaded. This message will disappear when all data is loaded.
Specify your search results
Select one or more organisms in this record:
This record set is specific for:
Homo sapiens
UNIPROT: P31327


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


The taxonomic range for the selected organisms is: Homo sapiens

EC NUMBER
COMMENTARY hide
6.3.4.16
-
RECOMMENDED NAME
GeneOntology No.
carbamoyl-phosphate synthase (ammonia)
REACTION
REACTION DIAGRAM
COMMENTARY hide
ORGANISM
UNIPROT
LITERATURE
2 ATP + NH3 + hydrogencarbonate = 2 ADP + phosphate + carbamoyl phosphate
show the reaction diagram
depending on their physiological role, carbonyl phosphate synthetases uses either glutamine or free ammonia as the nitrogen donor for carbamoyl phosphate synthesis, all enzymes contain the structurell equivalent of a triad-type glutamine amidotransferase, GAT, domain
-
REACTION TYPE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
amination
-
-
-
-
PATHWAY
BRENDA Link
KEGG Link
MetaCyc Link
urea cycle
Arginine biosynthesis
-
-
Alanine, aspartate and glutamate metabolism
-
-
Nitrogen metabolism
-
-
Metabolic pathways
-
-
Microbial metabolism in diverse environments
-
-
SYSTEMATIC NAME
IUBMB Comments
carbon-dioxide:ammonia ligase (ADP-forming, carbamate-phosphorylating)
The enzyme catalyses the first committed step in the urea cycle. The reaction proceeds via three separate chemical reactions: phosphorylation of hydrogencarbonate to carboxyphosphate; a nucleophilic attack of ammonia on carboxyphosphate yielding carbamate; and the phosphorylation of carbamate forming carbamoyl phosphate. Two moles of ATP are utilized for the synthesis of one molecule of carbamyl phosphate, making the reaction essentially irreversible. The enzyme requires the allosteric activator N-acetyl-L-glutamate. cf. EC 6.3.5.5, carbamoyl-phosphate synthase (glutamine-hydrolysing).
CAS REGISTRY NUMBER
COMMENTARY hide
9026-23-7
-
ORGANISM
COMMENTARY hide
LITERATURE
UNIPROT
SEQUENCE DB
SOURCE
GENERAL INFORMATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
malfunction
single nucleotide polymorphisms in the gene encoding CPS1 are involved, together with mutations in other genes encoding for other enzymes, in the development of severe asthma by African American children, which show a higher rate of this disease compared to other ethnics, overview. A combination of four single nucleotide polymorphisms (SNPs) within GSNOR, adrenergic receptor beta 2, and carbamoyl phosphate synthetase-1 give a 70% predictive value for lack of response to therapy
metabolism
-
CPSI is the first urea cycle enzyme
physiological function
-
CPSI is a key regulator of the urea cycle for ammonia detoxification in animals, including humans
malfunction
SUBSTRATE
PRODUCT                       
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
Reversibility
r=reversible
ir=irreversible
?=not specified
2 ATP + NH3 + CO2 + H2O
2 ADP + phosphate + carbamoyl phosphate
show the reaction diagram
ATP + NH3 + CO2 + H2O
ADP + phosphate + carbamoyl phosphate
show the reaction diagram
-
-
-
-
?
ATP + NH4+ + HCO3-
ADP + phosphate + carbamoyl phosphate
show the reaction diagram
-
-
-
-
?
ATP + NH4+ + HCO3- + H2O
ADP + phosphate + carbamoyl phosphate
show the reaction diagram
ATP + NH3 + CO2 + H2O
ADP + phosphate + carbamoyl phosphate
show the reaction diagram
ATP + NH4+ + CO2 + H2O
ADP + phosphate + carbamoylphosphate
show the reaction diagram
ATP + NH4+ + HCO3-
ADP + phosphate + carbamoyl phosphate
show the reaction diagram
additional information
?
-
NATURAL SUBSTRATES
NATURAL PRODUCTS
REACTION DIAGRAM
ORGANISM
UNIPROT
COMMENTARY
(Substrate) hide
LITERATURE
(Substrate)
COMMENTARY
(Product) hide
LITERATURE
(Product)
REVERSIBILITY
r=reversible
ir=irreversible
?=not specified
2 ATP + NH3 + CO2 + H2O
2 ADP + phosphate + carbamoyl phosphate
show the reaction diagram
-
-
-
-
?
ATP + NH3 + CO2 + H2O
ADP + phosphate + carbamoyl phosphate
show the reaction diagram
-
-
-
-
?
ATP + NH4+ + HCO3-
ADP + phosphate + carbamoyl phosphate
show the reaction diagram
-
-
-
-
?
ATP + NH4+ + HCO3- + H2O
ADP + phosphate + carbamoyl phosphate
show the reaction diagram
ATP + NH3 + CO2 + H2O
ADP + phosphate + carbamoyl phosphate
show the reaction diagram
ATP + NH4+ + HCO3-
ADP + phosphate + carbamoyl phosphate
show the reaction diagram
-
-
-
?
additional information
?
-
COFACTOR
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
METALS and IONS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
Mn2+
-
can substitute for Mg2+ in activation, more effective on a molar basis, free Mn2+ at 5 mM and above inhibits
INHIBITORS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
glycerol
-
in the presence of N-acetyl-L-glutamate the enzyme is inhibited by increasing concentrations of glycerol
Mg2+
-
above 20 mM
Mn2+
-
at or above 5 mM
additional information
-
the urea cycle enzyme CPS1 is the antigen for Hep Par 1 antibody
-
ACTIVATING COMPOUND
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
glycerol
-
the recombinant enzyme CPS1 is activated by glycerol in the absence of N-acetyl-L-glutamate
N-acetyl-L-beta-phenylglutamate
-
lower activation of CPSI compared to N-acetyl-L-glutamate
N-acetyl-L-glutamate
N-acetylglutamate
N-carbamyl-L-glutamate
-
-
acetylglutamate
N-acetylglutamate
-
essential
N-carbamoylglutamate
-
effective activator, Km: 2.0 mM
KM VALUE [mM]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
0.43 - 1.92
ATP
2.44 - 242
HCO3-
0.29 - 0.44
N-acetylglutamate
0.35 - 1.3
NH4+
0.26
ATP
-
-
2.2
CoATP2-
-
HCO3-
6.7
HCO3-
-
-
1.1
MgATP2-
-
-
0.8 - 1.3
NH4+
additional information
additional information
-
TURNOVER NUMBER [1/s]
SUBSTRATE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
IMAGE
5.54 - 5.73
NH3
additional information
additional information
-
-
-
SPECIFIC ACTIVITY [µmol/min/mg]
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
0.43
-
purified recombinant tagged mutant C1327A
0.47
-
purified recombinant tagged mutant C1337A
0.86
-
purified recombinant tagged wild-type enzyme
pH OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
7.4
-
assay at
7.6
-
assay at
7.8
-
-
pH RANGE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
7 - 8.5
-
50% of maximal activity at pH 7.0 and 8.5
TEMPERATURE OPTIMUM
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
25 - 30
-
assay at
37
-
assay at
pI VALUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
6.3
-
sequence calculation
SOURCE TISSUE
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
SOURCE
cultured human primary hepatocytes, express CPS1 at abundant levels
Manually annotated by BRENDA team
-
expressed at higher level in adult testis than in fetal testis
Manually annotated by BRENDA team
-
hepatocarcinoma cell line, suppression of CPS1 expression occurs at the transcriptional level
Manually annotated by BRENDA team
-
hepatoid tumors of gastric and yolk sac
Manually annotated by BRENDA team
-
hepatocarcinoma cell line, suppression of CPS1 expression occurs at the transcriptional level
Manually annotated by BRENDA team
-
hepatocarcinoma cell line, suppression of CPS1 expression occurs at the transcriptional level
Manually annotated by BRENDA team
additional information
LOCALIZATION
ORGANISM
UNIPROT
COMMENTARY hide
GeneOntology No.
LITERATURE
SOURCE
PDB
SCOP
CATH
UNIPROT
ORGANISM
Homo sapiens;
MOLECULAR WEIGHT
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
192000
-
recombinant enzyme, gel filtration
202000
-
native enzyme, gel filtration
160000
-
1 * 160000, SDS-PAGE in presence of a reducing agent
165000 - 178000
-
gel filtration, density gradient centrifugation
165000
-
1 * 165000, SDS-PAGE
166000
-
mass spectrometry
190000
-
gel filtration
SUBUNITS
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
monomer
TEMPERATURE STABILITY
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
37
-
4 h, 30% loss of activity
46
-
5 min, 25% loss of activity
55
-
5 min, 80% loss of activity
STORAGE STABILITY
ORGANISM
UNIPROT
LITERATURE
4°C, stable for at least 1 month
-
Purification/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
HisTrap column chromatography
-
Cloned/COMMENTARY
ORGANISM
UNIPROT
LITERATURE
expressed in Escherichia coli DH10Bac cells
-
gene CPS1, located on chromosome 2, genotyping, overview
gene CPSI, DNA and amino acid sequence determination and analysis, expression of the N-terminally His6-FLAG-tagged enzyme and mutant T1406D in Schizosaccharomyces pombe from pESP5, expression of mature protein of 1462 amino acid residues with the first 39 amino acids of the precursor protein replaced by a methionyl residue
-
gene CPSI, expression of the N-terminally His6-FLAG-tagged enzyme in Schizosaccharomyces pombe from pESP5
-
gene CPS1 is located on chromosome 2q35, genotyping and cloning of wild-type and mutant CPSIs in Cos7 and HeLa cells, which show increased activity with the wild-type gene, overview
-
EXPRESSION
ORGANISM
UNIPROT
LITERATURE
human hepatocellular carcinoma cells do not express CPS1, whereas cultured human primary hepatocytes express abundant levels. CPS1 is silenced or down-regulated in liver tumor tissues compared with the matched noncancerous tissues. The expression of CPS1 in human hepatocellular carcinoma cells is restored with demethylation agent, 5-azacytidine. Two CpG dinucleotides, located near the transcription start site, and a CpG-rich region in the first intron are hypermethylated in human hepatocellular carcinoma cells
ENGINEERING
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
A1378T
-
the carbamoyl-phosphate synthetase deficiency-causing mutation greatly decreases enzyme activity
A438P
-
inactive
Al38P
-
the carbamoyl-phosphate synthetase deficiency-causing mutation greatly decreases enzyme activity
C1327A
-
the mutant shows reduced activity compared to the wild-type enzyme, the mutation significantly alters activity at the domain C ATP site, binding of N-acetylglutamate is affected, overview
C1337A
-
the mutant shows reduced activity compared to the wild-type enzyme, the mutation significantly alters activity at the domain C ATP site, binding of N-acetylglutamate is affected, overview
G1376S
-
the mutation has no detectable effect on activity
L1381S
-
the mutation is clearly disease-causing (carbamoyl-phosphate synthetase deficiency), since it induces strong enzyme instability
L390R
-
the mutation is clearly disease-causing (carbamoyl-phosphate synthetase deficiency), since it induces strong enzyme instability
N355D
-
the carbamoyl-phosphate synthetase deficiency-causing mutation greatly decreases enzyme activity
T1406D
-
naturally occurring single nucleotide polymorphism, phenotype, overview
T1443A
-
the carbamoyl-phosphate synthetase deficiency-causing mutation greatly decreases enzyme activity
T344A
-
the mutation has no detectable effect on activity
T544M
-
the carbamoyl-phosphate synthetase deficiency-causing mutation greatly decreases enzyme activity
W1410K
-
site-directed mutagenesis, the mutant binds N-acetyl-L-beta-phenylglutamate at the N-acetyl-L-glutamate binding site
Y389C
-
the carbamoyl-phosphate synthetase deficiency-causing mutation greatly decreases enzyme activity
R1262X
-
a premature stop codon mutation naturally occuring in carbamoyl phosphate synthetase 1 deficiency, CPS1D
R803G
-
naturally occuring missense mutation involved in carbamoyl phosphate synthetase 1 deficiency, CPS1D
T1405N
-
significant change in CPSI enzymatic function
additional information
APPLICATION
ORGANISM
UNIPROT
COMMENTARY hide
LITERATURE
medicine
human hepatocellular carcinoma cells do not express CPS1, whereas cultured human primary hepatocytes express abundant levels. CPS1 is silenced or down-regulated in liver tumor tissues compared with the matched noncancerous tissues. The expression of CPS1 in human hepatocellular carcinoma cells is restored with demethylation agent, 5-azacytidine. Two CpG dinucleotides, located near the transcription start site, and a CpG-rich region in the first intron are hypermethylated in human hepatocellular carcinoma cells