Cloned (Comment) | Organism |
---|---|
expression of wild-type and mutant enzymes | Escherichia coli |
Protein Variants | Comment | Organism |
---|---|---|
C54S | site-directed mutagenesis, mutation results in proteins devoid of bound zinc and unable to release formate from the imidazole ring of GTP or from the intermediate analogue 2-amino-5-formylamino-6-ribosylamino-4(3H)-pyrimidinone 5'-triphosphate, however, the mutant enzyme is still capable to release diphosphate from GTP and from the formamide-type intermediate analogue | Escherichia coli |
C65S | site-directed mutagenesis, mutation results in proteins devoid of bound zinc and unable to release formate from the imidazole ring of GTP or from the intermediate analogue 2-amino-5-formylamino-6-ribosylamino-4(3H)-pyrimidinone 5'-triphosphate, however, the mutant enzyme is still capable to release diphosphate from GTP and from the formamide-type intermediate analogue | Escherichia coli |
C67S | site-directed mutagenesis, mutation results in proteins devoid of bound zinc and unable to release formate from the imidazole ring of GTP or from the intermediate analogue 2-amino-5-formylamino-6-ribosylamino-4(3H)-pyrimidinone 5'-triphosphate, however, the mutant enzyme is still capable to release diphosphate from GTP and from the formamide-type intermediate analogue | Escherichia coli |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Zn2+ | wild-type enzyme contains 0.71 mol Zn2+ per mol of subunit, while the content in the mutant enzymes is reduced to below 0.1 mol Zn2+ per mol of subunit, essential for activity, bound to the active site, required for ring opening and formate release with zinc acting as a Lewis acid, which activates the 2 water molecules involved in the sequential hydrolysis of 2 carbon-nitrogen bonds | Escherichia coli |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
GTP + H2O | Escherichia coli | first committed step in the biosynthesis of riboflavin, overview | formate + 2,5-diamino-6-hydroxy-4-(5-phosphoribosylamino)pyrimidine + diphosphate | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Escherichia coli | - |
- |
- |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
GTP + 4 H2O = formate + 2,5-diamino-6-hydroxy-4-(5-phospho-D-ribosylamino)pyrimidine + 2 phosphate | ordered reaction mechanism, in which the hydrolytic release of diphosphate preceeds the hydrolytic attack of the imidazole ring, ring opening and formate release are dependent on zinc bound to the active site, overview | Escherichia coli |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
additional information | - |
activity of the mutant enzyme C54S, C65S, and C67S with the different substrates, overview, best substrate is GTP being cleaved to GMP | Escherichia coli |
0.002 | - |
purified recombinant mutant C65S, substrate GTP cleaved to GMP | Escherichia coli |
0.003 | - |
purified recombinant mutant C67S, substrate GTP cleaved to GMP | Escherichia coli |
0.01 | - |
purified recombinant mutant C54S, substrate GTP cleaved to GMP | Escherichia coli |
0.015 | - |
purified recombinant wild-type enzyme, substrate 2-amino-5-formylamino-6-ribosylamino-4(3H)-pyrimidinone triphosphate cleaved to 2-amino-5-formylamino-6-ribosylamino-4(3H)-pyrimidinone 5'-phosphate | Escherichia coli |
0.016 | - |
purified recombinant wild-type enzyme, substrate GTP cleaved to GMP | Escherichia coli |
0.025 | - |
purified recombinant wild-type enzyme, substrate dGTP cleaved to dGMP | Escherichia coli |
0.038 | - |
purified recombinant wild-type enzyme, substrate dGTP cleaved to 2,5-diamino-6-hydroxy-4-(5-phospho-deoxyribosylamino)pyrimidine | Escherichia coli |
0.122 | - |
purified recombinant wild-type enzyme, substrate 2-amino-5-formylamino-6-ribosylamino-4(3H)-pyrimidinone triphosphate cleaved to 2,5-diamino-6-hydroxy-4-(5-phosphoribosylamino)pyrimidine | Escherichia coli |
0.182 | - |
purified recombinant wild-type enzyme, substrate GTP cleaved to 2,5-diamino-6-hydroxy-4-(5-phosphoribosylamino)pyrimidine | Escherichia coli |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
2-amino-5-formylamino-6-ribosylamino-4(3H)-pyrimidinone triphosphate + 2 H2O | formamide-type intermediate analogue | Escherichia coli | formate + 2,5-diamino-6-ribosylamino-4(3H)-pyrimidinone 5'-phosphate + diphosphate | - |
? | |
2-amino-5-formylamino-6-ribosylamino-4(3H)-pyrimidinone triphosphate + H2O | formamide-type intermediate analogue | Escherichia coli | 2-amino-5-formylamino-6-ribosylamino-4(3H)-pyrimidinone 5'-phosphate + diphosphate | - |
? | |
dGTP + H2O | - |
Escherichia coli | formate + 2,5-diamino-6-hydroxy-4-(5-phospho-deoxyribosylamino)pyrimidine + diphosphate | - |
? | |
GTP + H2O | - |
Escherichia coli | formate + 2,5-diamino-6-hydroxy-4-(5-phosphoribosylamino)pyrimidine + diphosphate | - |
? | |
GTP + H2O | first committed step in the biosynthesis of riboflavin, overview | Escherichia coli | formate + 2,5-diamino-6-hydroxy-4-(5-phosphoribosylamino)pyrimidine + diphosphate | - |
? |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | - |
assay at | Escherichia coli |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
8 | - |
assay at | Escherichia coli |