Activating Compound | Comment | Organism | Structure |
---|---|---|---|
dithiothreitol | ArfB is not active in the absence of 2 mM dithiothreitol | Methanocaldococcus jannaschii |
Cloned (Comment) | Organism |
---|---|
in Escherichia coli | Methanocaldococcus jannaschii |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
1 | - |
2-amino-5-formylamino-6-(D-ribosylamino)pyrimidin-4(3H)-one 5'-phosphate | pH 7.2, 70°C, apparent Km-value is about 1 mM at a concentration of 2 mM Fe2+, type of curve is typically indicative of homomeric cooperativity and suggests that ArfB may exhibit positive cooperative substrate binding | Methanocaldococcus jannaschii |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Fe2+ | addition of more than 1 mM Fe2+ increases the rate of 2,5-diamino-6-ribosylamino-4(3H)-pyrimidinone 5'-phosphate production by more than 10fold, purified enzyme contains both 1.4 mol iron and 6.2 mol magnesium per mol of protomer, maximum activity of Chelex-treated enzyme with added Fe2+ is 30% that of the untreated enzyme indicating that the apoenzyme cannot be fully reconstituted with the addition of just one metal | Methanocaldococcus jannaschii | |
Mg2+ | enzyme contains both 1.4 mol Fe2+ and 6.2 mol Mg2+ per mol of protomer | Methanocaldococcus jannaschii | |
Mn2+ | addition of more than 1 mM Mn2+ increases the rate of 2,5-diamino-6-ribosylamino-4(3H)-pyrimidinone 5'-phosphate production by more than 10fold, maximum activity of Chelex-treated enzyme with added Mn2+ is 30% that of the untreated enzyme indicating that the apoenzyme cannot be fully reconstituted with the addition of just one metal | Methanocaldococcus jannaschii | |
Zn2+ | zinc is associated with the purified protein, 1.5 mol/protomer, despite the presence of zinc in the protein, addition of Zn(II) to the incubation mixture containing purified enzyme or apo-enzyme does not activate ArfB | Methanocaldococcus jannaschii |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
25000 | - |
2 * 25000 | Methanocaldococcus jannaschii |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
2-amino-5-formylamino-6-(D-ribosylamino)pyrimidin-4(3H)-one 5'-phosphate + H2O | Methanocaldococcus jannaschii | enzyme catalyzes the second step in archaeal riboflavin and 7,8-didemethyl-8-hydroxy-5-deazariboflavin biosynthesis. The archaeal pathway begins with an archaeal-specific GTP cyclohydrolase IIa (EC 3.5.4.29) that hydrolyzes the imidazole ring of GTP. The bacterial enzyme, EC 3.5.4.25 (GTP cyclohydrolase II) catalyzes both reactions | 2,5-diamino-6-(D-ribosylamino)pyrimidin-4(3H)-one 5'-phosphate + formate | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Methanocaldococcus jannaschii | Q57580 | - |
- |
Purification (Comment) | Organism |
---|---|
purified by anion-exchange chromatography | Methanocaldococcus jannaschii |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
6 | - |
Vmax at a concentration of 2 mM Fe2+, 5 mM MgCl2, 10 mM dithiothreitol and 25 mM TES, pH 7.2 | Methanocaldococcus jannaschii |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
2-amino-5-formylamino-6-(D-ribosylamino)pyrimidin-4(3H)-one 5'-phosphate + H2O | - |
Methanocaldococcus jannaschii | 2,5-diamino-6-(D-ribosylamino)pyrimidin-4(3H)-one 5'-phosphate + formate | - |
? | |
2-amino-5-formylamino-6-(D-ribosylamino)pyrimidin-4(3H)-one 5'-phosphate + H2O | enzyme catalyzes the second step in archaeal riboflavin and 7,8-didemethyl-8-hydroxy-5-deazariboflavin biosynthesis. The archaeal pathway begins with an archaeal-specific GTP cyclohydrolase IIa (EC 3.5.4.29) that hydrolyzes the imidazole ring of GTP. The bacterial enzyme, EC 3.5.4.25 (GTP cyclohydrolase II) catalyzes both reactions | Methanocaldococcus jannaschii | 2,5-diamino-6-(D-ribosylamino)pyrimidin-4(3H)-one 5'-phosphate + formate | - |
? |
Subunits | Comment | Organism |
---|---|---|
dimer | 2 * 25000 | Methanocaldococcus jannaschii |
Synonyms | Comment | Organism |
---|---|---|
2-amino-5-formylamino-6-ribosylamino-4(3H)-pyrimidinone 5'-monophosphate deformylase | - |
Methanocaldococcus jannaschii |
ArfB | - |
Methanocaldococcus jannaschii |
MJ0116 | - |
Methanocaldococcus jannaschii |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
70 | - |
assay at | Methanocaldococcus jannaschii |
Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|
80 | - |
stable at | Methanocaldococcus jannaschii |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7.2 | - |
assay at | Methanocaldococcus jannaschii |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
6.5 | 8.5 | pH 6.5: about 80% of maximal activity, pH 8.5: about 40% of maximal activity | Methanocaldococcus jannaschii |