Activating Compound | Comment | Organism | Structure |
---|---|---|---|
IMP | - |
Escherichia coli | |
L-ornithine | - |
Escherichia coli |
Cloned (Comment) | Organism |
---|---|
cloning of car B wild-type and mutant enzymes | Escherichia coli |
Protein Variants | Comment | Organism |
---|---|---|
A182V | reduced apparent affinity for HCO3-, sensitivity toward UMP is unchanched in comparison to wild-type enzyme | Escherichia coli |
A182V/S948F | mutant is insensitive towards pyrimidine and purine nucleosides, activation by ornithine, although the affinity for this ligand is fivefold reduced in comparison to wild-type enzyme | Escherichia coli |
G824D | strongly reduced affinity for ornithine in comparison to wild-type enzyme | Escherichia coli |
P165S | reduced apparent affinity for HCO3-, sensitivity toward UMP is increased in comparison to wild-type enzyme | Escherichia coli |
P170L | reduced apparent affinity for HCO3-, sensitivity toward UMP is increased in comparison to wild-type enzyme | Escherichia coli |
P360L | UMP still inhibits the activity of the mutant enzyme, 30fold reduced affinity for ornithine and 20fold reduced affinity for IMP in comparison to wild-type enzyme | Escherichia coli |
S743N | minor modification of kinetic parameters in comparison to wild-type enzyme | Escherichia coli |
S743N/G824D | strongly reduced affinity for ornithine in comparison to wild-type enzyme | Escherichia coli |
S948F | mutant enzyme is unsensitive to UMP and IMP, but is still activated by ornithine, although to a reduced extent | Escherichia coli |
T1042I | greatly reduced activation by ornithine, the affinities for both UMP and IMP are reduced in comparison to wild-type enzyme in comparison to wild-type enzyme | Escherichia coli |
T1042I | mutation reduces activation by ornithine, the mutated enzyme is still sensitive to UMP and IMP | Escherichia coli |
T800F | reduced affinity for ornithine, increased sensitivity for UMP in comparison to wild-type enzyme | Escherichia coli |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
UMP | - |
Escherichia coli |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.12 | - |
L-glutamine | pH 7.5, 37°C, value of wild-type enzyme in comparison to values of mutant enzymes | Escherichia coli | |
1.2 | - |
HCO3- | pH 7.5, 37°C, value of wild-type enzyme in comparison to values of mutant enzymes | Escherichia coli |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 ATP + L-Gln + HCO3- | Escherichia coli | enzyme is a key enzyme in the pyrimidine nucleotide and arginine biosynthetic pathways | 2 ADP + phosphate + L-Glu + carbamoyl phosphate | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | - |
K-12 | - |
Purification (Comment) | Organism |
---|---|
recombinant wild-type and mutant enzymes | Escherichia coli |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
2 ATP + L-glutamine + hydrogencarbonate + H2O = 2 ADP + phosphate + L-glutamate + carbamoyl phosphate | two residues, Ser948 and Thr1042, appear crucial for allosteric regulation of enzyme | Escherichia coli |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
2 ATP + L-Gln + HCO3- | - |
Escherichia coli | 2 ADP + phosphate + L-Glu + carbamoyl phosphate | - |
? | |
2 ATP + L-Gln + HCO3- | enzyme is a key enzyme in the pyrimidine nucleotide and arginine biosynthetic pathways | Escherichia coli | 2 ADP + phosphate + L-Glu + carbamoyl phosphate | - |
? |
Ki Value [mM] | Ki Value maximum [mM] | Inhibitor | Comment | Organism | Structure |
---|---|---|---|---|---|
0.005 | - |
UMP | pH 7.5, 37°C, value of wild-type enzyme in comparison to values of mutant enzymes | Escherichia coli |