Cloned (Comment) | Organism |
---|---|
overexpression in Escherichia coli strain EK1104 transformed with plasmid pEK15212 containing the Escherichia coli pyrBI gene | Escherichia coli |
Crystallization (Comment) | Organism |
---|---|
purified recombinant ATCase in complex with UTP, CTP, or dCTP, dialysis of 20 mg/ml protein against 40 mM sodium citrate, 1 mM 2-mercaptoethanol, 0.2 mM EDTA, and 1.0 mM CTP, pH 5.7, at 20°C, 1 week, transfer of dialysis buttons to 2 mL of crystallization buffer with 5 mM UTP and 5 mM MgCl2 and equilibration for 12 h, and to crystallization buffer containing 5 mM UTP and 5 mM MgCl2 for 12 h, respectively, cryoprotection in 20% 2-methyl-2,4-pentanediol in UTP-Mg2+ crystallization buffer, X-ray diffraction structure determination and analysis at 1.9-2.1 A resolution | Escherichia coli |
Protein Variants | Comment | Organism |
---|---|---|
D19A | a regulatory mutant, which does not exhibit UTP synergistic inhibition | Escherichia coli |
H20A | a regulatory mutant, which does not exhibit UTP synergistic inhibition | Escherichia coli |
K56A | a regulatory mutant, which does not exhibit UTP synergistic inhibition | Escherichia coli |
K60A | a regulatory mutant, which does not exhibit UTP synergistic inhibition | Escherichia coli |
K6A | a regulatory mutant, which does not exhibit UTP synergistic inhibition | Escherichia coli |
L7A | a regulatory mutant, which does not exhibit UTP synergistic inhibition | Escherichia coli |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
CTP | demetaled CTP, synergistic inhibition with UTP, while UTP alone has little or no influence on the enzyme activity, mechanism, overview. Binding of UTP can enhance the binding of CTP and presence of a metal ion such as Mg2+ is required for synergistic inhibition. Structure of the ATCase-CTP-UTP-Mg2+ complex | Escherichia coli | |
dCTP | - |
Escherichia coli | |
additional information | conformational changes due to nucleotide binding, overview | Escherichia coli | |
UTP | inhibition with CTP, while UTP alone has little or no influence on the enzyme activity, mechanism, overview. UTP, in the presence of dCTP or CTP, binds at a site on a regulatory side chain that does not overlap the CTP/dCTP site, and the triphosphates of the two nucleotides are parallel to each other with a metal ion, in this case Mg2+, coordinated between the beta- and gamma-phosphates of the two nucleotides. UTP binds more tightly in the presence of CTP. Structure of the ATCase-CTP-UTP-Mg2+ complex | Escherichia coli |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | allosteric mechanism with metal ion involvement, overview | Escherichia coli |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Mg2+ | required for synergistic inhibition of the enzyme by CTP and UTP, metal binding site in the allosteric regulatory site of ATCase, overview | Escherichia coli |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-aspartate + carbamoyl phosphate | Escherichia coli | - |
phosphate + N-carbamoyl-L-aspartate | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | P0A786 | - |
- |
Purification (Comment) | Organism |
---|---|
recombinant enzyme from Escherichia coli strain EK114 by anion exchange chromatography, ammonium sulfate fractionation, and hydrophobic interaction chromatography | Escherichia coli |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-aspartate + carbamoyl phosphate | - |
Escherichia coli | phosphate + N-carbamoyl-L-aspartate | - |
? | |
additional information | conformational changes due to nucleotide binding, overview | Escherichia coli | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
aspartate transcarbamoylase | - |
Escherichia coli |
ATCase | - |
Escherichia coli |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
25 | - |
assay at | Escherichia coli |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7 | - |
assay at | Escherichia coli |
General Information | Comment | Organism |
---|---|---|
metabolism | aspartate transcarbamoylase allosterically regulates pyrimidine nucleotide biosynthesis | Escherichia coli |
physiological function | aspartate transcarbamoylase allosterically regulates pyrimidine nucleotide biosynthesis | Escherichia coli |