EC Number | Activating Compound | Comment | Organism | Structure |
---|---|---|---|---|
6.3.5.5 | N-acetylglutamate | carbamoyl-phosphate synthase III: requirement for N-acetylglutamate | Squalus acanthias | |
6.3.5.5 | N-acetylglutamate | carbamoyl-phosphate synthase II: no requirement for N-acetylglutamate | Mammalia | |
6.3.5.5 | N-acetylglutamate | carbamoyl-phosphate synthase II: no requirement for N-acetylglutamate | Escherichia coli | |
6.3.5.5 | NEM | 250fold activation of glutaminase activity. Irreversible inactivation of synthetase activity | Escherichia coli | |
6.3.5.5 | Orn | activates | Escherichia coli | |
6.3.5.5 | thiol | required for Gln-dependent activity | Escherichia coli |
EC Number | Cloned (Comment) | Organism |
---|---|---|
6.3.5.5 | - |
Escherichia coli |
EC Number | Protein Variants | Comment | Organism |
---|---|---|---|
6.3.5.5 | C269G | Cys269Gly and Cys269Ser mutants bind significant amounts of Gln but do not hydrolyze Gln. The mutants are able to catalyze carbamoyl-phosphate formation with NH4+ as nitrogen donor, at a rate equal to that of the wild type enzyme. The mutant enzyme catalyzes ATP synthesis from ADP and carbamoyl phosphate at the usual rates. Substantial increase in bicarbonate-dependent ATPase | Escherichia coli |
6.3.5.5 | C269S | Cys269Gly and Cys269Ser mutants bind significant amounts of Gln but do not hydrolyze Gln. The mutants are able to catalyze carbamoyl-phosphate formation with NH4+ as nitrogen donor, at a rate equal to that of the wild type enzyme. The mutant enzyme catalyzes ATP synthesis from ADP and carbamoyl phosphate at the usual rates. Substantial increase in bicarbonate-dependent ATPase | Escherichia coli |
EC Number | General Stability | Organism |
---|---|---|
6.3.5.5 | treatment with 1 M potassium thiocyanate results in reversible dissociation into its subunits which retain catalytic activity | Escherichia coli |
EC Number | Inhibitors | Comment | Organism | Structure |
---|---|---|---|---|
6.3.5.5 | Alkyl hydrazines | inhibits Gln-dependent activity, but not NH4+-dependent activity | Escherichia coli | |
6.3.5.5 | H2O2 | 0.2 mM, inhibits Gln-dependent activity. No effect on the activity with NH4+ in carbamoyl-phosphate synthase reaction | Escherichia coli | |
6.3.5.5 | hydroxylamine | inhibits Gln-dependent activity, but not NH4+-dependent activity; the inhibitory effect is much greater at pH 9 than at pH 6 | Escherichia coli | |
6.3.5.5 | L-2-Amino-4-oxo-5-chloropentanoate | selective inactivation of Gln-dependent activity | Escherichia coli | |
6.3.5.5 | NEM | irreversible inactivation of synthetase activity. Increase of glutaminase activity | Escherichia coli | |
6.3.5.5 | potassium cyanate | inhibits Gln-dependent activity, but not NH4+-dependent activity | Escherichia coli | |
6.3.5.5 | UMP | - |
Escherichia coli |
EC Number | KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|---|
6.3.5.5 | 0.38 | - |
L-Gln | - |
Escherichia coli | |
6.3.5.5 | 93 | - |
NH4+ | - |
Escherichia coli |
EC Number | Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|---|
6.3.5.5 | cytosol | - |
Mammalia | 5829 | - |
EC Number | Metals/Ions | Comment | Organism | Structure |
---|---|---|---|---|
6.3.5.5 | K+ | required for maximal activity | Escherichia coli | |
6.3.5.5 | Mg2+ | free Mg2+ is required in addition to MgATP2- | Escherichia coli | |
6.3.5.5 | Mn2+ | maximal activity at concentration of Mn2+ approximately equal to the ATP concentration | Escherichia coli | |
6.3.5.5 | NH4+ | can replace K+ in activation | Escherichia coli |
EC Number | Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|---|
6.3.5.5 | 40000 | - |
1 * 40000, subunit contains the binding site for glutamine, + 1 * 133000, subunit contains the binding sites for NH4+, HCO3-, ATP, and the allosteric effectors. The light and heavy subunits are encoded by the genetically linked car A and car B genes, respectively | Escherichia coli |
6.3.5.5 | 133000 | - |
1 * 40000, subunit contains the binding site for glutamine, + 1 * 133000, subunit contains the binding sites for NH4+, HCO3-, ATP, and the allosteric effectors. The light and heavy subunits are encoded by the genetically linked car A and car B genes, respectively | Escherichia coli |
EC Number | Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|---|
6.3.5.5 | ATP + L-Gln + HCO3- | Elasmobranchii | functions in the synthesis of urea used in osmoregulation | ? | - |
? | |
6.3.5.5 | ATP + L-Gln + HCO3- | Mammalia | catalyzes the first step of de novo pyrimidine biosynthesis | ? | - |
? |
EC Number | Organism | UniProt | Comment | Textmining |
---|---|---|---|---|
6.3.5.5 | Agaricus bisporus | - |
- |
- |
6.3.5.5 | Elasmobranchii | - |
- |
- |
6.3.5.5 | Escherichia coli | - |
- |
- |
6.3.5.5 | Fresh-water teleost | - |
- |
- |
6.3.5.5 | Mammalia | - |
- |
- |
6.3.5.5 | Squalus acanthias | - |
- |
- |
EC Number | Reaction | Comment | Organism | Reaction ID |
---|---|---|---|---|
6.3.5.5 | 2 ATP + L-glutamine + hydrogencarbonate + H2O = 2 ADP + phosphate + L-glutamate + carbamoyl phosphate | mechanism, formation of enzyme-bound carboxy phosphate | Escherichia coli |
EC Number | Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|---|
6.3.5.5 | 2 ATP + L-Gln + HCO3- | - |
Mammalia | 2 ADP + phosphate + L-Glu + carbamoyl phosphate | - |
? | |
6.3.5.5 | 2 ATP + L-Gln + HCO3- | - |
Squalus acanthias | 2 ADP + phosphate + L-Glu + carbamoyl phosphate | - |
? | |
6.3.5.5 | 2 ATP + L-Gln + HCO3- | - |
Elasmobranchii | 2 ADP + phosphate + L-Glu + carbamoyl phosphate | - |
? | |
6.3.5.5 | 2 ATP + L-Gln + HCO3- | - |
Fresh-water teleost | 2 ADP + phosphate + L-Glu + carbamoyl phosphate | - |
? | |
6.3.5.5 | 2 ATP + L-Gln + HCO3- | - |
Agaricus bisporus | 2 ADP + phosphate + L-Glu + carbamoyl phosphate | - |
? | |
6.3.5.5 | 2 ATP + L-Gln + HCO3- | overall reaction is irreversible | Escherichia coli | 2 ADP + phosphate + L-Glu + carbamoyl phosphate | - |
? | |
6.3.5.5 | 2 ATP + NH4+ + HCO3- | - |
Escherichia coli | 2 ADP + phosphate + carbamoyl phosphate | - |
? | |
6.3.5.5 | ATP + L-Gln + HCO3- | functions in the synthesis of urea used in osmoregulation | Elasmobranchii | ? | - |
? | |
6.3.5.5 | ATP + L-Gln + HCO3- | catalyzes the first step of de novo pyrimidine biosynthesis | Mammalia | ? | - |
? |
EC Number | Subunits | Comment | Organism |
---|---|---|---|
6.3.5.5 | dimer | 1 * 40000, subunit contains the binding site for glutamine, + 1 * 133000, subunit contains the binding sites for NH4+, HCO3-, ATP, and the allosteric effectors. The light and heavy subunits are encoded by the genetically linked car A and car B genes, respectively | Escherichia coli |
6.3.5.5 | More | - |
Mammalia |
6.3.5.5 | More | enzyme can exist in different monomer conformations and states of association | Escherichia coli |
EC Number | pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|---|
6.3.5.5 | 4.2 | - |
and a second optimum at pH 9.5, glutaminase activity | Escherichia coli |
6.3.5.5 | 7.8 | 8.2 | - |
Escherichia coli |
6.3.5.5 | 9.5 | - |
and a second optimum at pH 4.2, glutaminase activity | Escherichia coli |
EC Number | Cofactor | Comment | Organism | Structure |
---|---|---|---|---|
6.3.5.5 | IMP | stimulates | Escherichia coli |