Cloned (Comment) | Organism |
---|---|
expression in Escherichia coli | Escherichia coli |
Crystallization (Comment) | Organism |
---|---|
wild-type cocrystallized with 4-nitroaminoimidazole ribonucleotide and mutants H45N and H45Q soaked with 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate | Escherichia coli |
Protein Variants | Comment | Organism |
---|---|---|
H45N | very low catalytic activity | Escherichia coli |
H45Q | very low catalytic activity | Escherichia coli |
H45W | very low catalytic activity | Escherichia coli |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.0226 | - |
5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate | wild-type, pH 7.5, 23°C | Escherichia coli |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | P0AG18 | - |
- |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
5-carboxyamino-1-(5-phospho-D-ribosyl)imidazole = 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate | common, buried carboxylate or CO2 binding site for substrate and product in a hydrophobic pocket, in which the carboxylate or CO2 interacts with backbone amides. The carboxylate orients the substrate for proton transfer from His45 to 5-carboxyamino-1-(5-phospho-D-ribosyl)imidazole to form an enzyme-bound aminoimidazole ribonucleotide and CO2 intermediate. subsequent movement of the aminoimidazole moiety reorients it for addition of CO2 at C4 to generate iso-5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate. H5 is now in a position to remove a C4 proton to produce 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate | Escherichia coli |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate | - |
Escherichia coli | 5-carboxyamino-1-(5-phospho-D-ribosyl)imidazole | - |
r | |
5-carboxyamino-1-(5-phospho-D-ribosyl)imidazole | - |
Escherichia coli | 5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate | - |
r |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.0004 | - |
5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate | mutant H45W, pH 7.5, 23°C | Escherichia coli | |
0.0012 | - |
5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate | mutant H45Q, pH 7.5, 23°C | Escherichia coli | |
0.0021 | - |
5-carboxyamino-1-(5-phospho-D-ribosyl)imidazole | mutant H45Q, pH 7.5, 23°C | Escherichia coli | |
15.5 | - |
5-carboxyamino-1-(5-phospho-D-ribosyl)imidazole | wild-type, pH 7.5, 23°C | Escherichia coli | |
15.6 | - |
5-amino-1-(5-phospho-D-ribosyl)imidazole-4-carboxylate | wild-type, pH 7.5, 23°C | Escherichia coli |