Crystallization (Comment) | Organism |
---|---|
purified recombinant iron-free E57A/E136A/D140A ferritin mutant variant, hanging drop vapor diffusion technique, mixing of 0.002 ml of 7 mg/ml protein in 20 mm Tris, pH 7.5, with 0.002 ml of reservoir solution composed of 1.6-2.0m MgCl2 and 0.1m bicine, pH 8.0, and equilibration against 0.6 ml reservoir solution, 8°C, 36 days to 10 days, for Fe2+-bound enzyme mutant, 0.1m bis-tris propane buffer at pH 6.5 is used for precipitation, X-ray diffraction structure determination and analysis at 1.50 A resolution, modeling | Lithobates catesbeianus |
Protein Variants | Comment | Organism |
---|---|---|
E130A | site-directed mutagenesis, inactive mutant | Lithobates catesbeianus |
E136A | site-directed mutagenesis, the mutant enzyme activity is reduced compared to wild-type due to a reduced ability of the variant nanocages to populate the ferroxidase sites Fe1 and Fe2, reduced catalytic activity compared to wild-type | Lithobates catesbeianus |
E57A | site-directed mutagenesis, the mutant enzyme activity is reduced compared to wild-type due to a reduced ability of the variant nanocages to populate the ferroxidase sites Fe1 and Fe2, reduced catalytic activity compared to wild-type | Lithobates catesbeianus |
E57A/E136A | site-directed mutagenesis, the mutant enzyme activity is reduced compared to wild-type due to a reduced ability of the variant nanocages to populate the ferroxidase sites Fe1 and Fe2, reduced catalytic activity compared to wild-type | Lithobates catesbeianus |
E57A/E136A/D140A | site-directed mutagenesis, inactive mutant, structure comparison to the wild-type enzyme. In the triple variant, only one Mg2+ ion is bound at the Fe1 site, and the ability of the variant cage to process Fe2+ ions is altered. The mutant shows reduced biomineralization efficiency | Lithobates catesbeianus |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | stopped-flow kinetics and single-turnover oxidoreductase kinetics, measuring diferric-peroxo intermediate and Fe3+ | Lithobates catesbeianus |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Cu2+ | required | Lithobates catesbeianus |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
480000 | - |
about, gel filtration, wild-type enzyme and mutant E57A/E136A/D140A | Lithobates catesbeianus |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
4 Fe(II) + 4 H+ + O2 | Lithobates catesbeianus | - |
4 Fe(III) + 2 H2O | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Lithobates catesbeianus | - |
- |
- |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
4 Fe(II) + 4 H+ + O2 | - |
Lithobates catesbeianus | 4 Fe(III) + 2 H2O | - |
? | |
4 Fe(II) + 4 H+ + O2 | two Fe2+ ions occupy sites Fe1 and Fe2 in the ferroxidase cavity, structure overview | Lithobates catesbeianus | 4 Fe(III) + 2 H2O | - |
? | |
additional information | formation of the diferric-peroxo (DFP) intermediate and of the ferric-oxo products of the ferroxidase reactions | Lithobates catesbeianus | ? | - |
? |
Synonyms | Comment | Organism |
---|---|---|
H' ferritin | - |
Lithobates catesbeianus |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
5 | 9 | assay at | Lithobates catesbeianus |
General Information | Comment | Organism |
---|---|---|
additional information | residue Asp140 and previously identified residues Glu57 andGlu136 are essential residues to promote the iron oxidation at the ferroxidase site, but the presence of these three carboxylate moieties in close proximity to the catalytic centers is not essential to achieve binding of the Fe2+ substrate to the diferric ferroxidase sites with the same coordination geometries as in the wild-type cages | Lithobates catesbeianus |
physiological function | ferritins are iron-storage nanocage proteins that catalyze the oxidation of Fe2+ to Fe3+ at ferroxidase sites. Ferroxidase activity in eukaryotic ferritin is controlled by accessory-iron-binding sites in the catalytic cavity, a ferroxidase-active cage, overview | Lithobates catesbeianus |