Cloned (Comment) | Organism |
---|---|
gene tll2470 or dpsA-Te, expression as soluble His-tagged protein in Escherichia coli strain BL21(DE3) | Thermosynechococcus vestitus |
Crystallization (Comment) | Organism |
---|---|
purified recombinant getagged DpsA-Te, 0.001 ml of 10 mg/ml protein in 20 mM Tris-HCl, pH 7.5, is mixed with 0.001 ml of reservoir solution containing 12% w/v PEG 8000 in 0.1 m MES, pH 6.0, 2 weeks, X-ray diffraction structure determination and analysis at 2.4 A resolution, molecular replacement | Thermosynechococcus vestitus |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | iron oxidation and incorporation kinetics, overview | Thermosynechococcus vestitus |
Localization | Comment | Organism | GeneOntology No. | Textmining |
---|---|---|---|---|
thylakoid membrane | possible localization of the protein at the thylakoid membranes due to presence of a long hydrophobic N-terminal tail | Thermosynechococcus vestitus | 42651 | - |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Zn2+ | DpsA-Te contains two Zn2+ bound at the ferroxidase center. The latter Zn2+ is displaced by incoming iron, such that Zn(II)-Fe(III) complexes are formed upon oxidation | Thermosynechococcus vestitus |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
20900 | - |
12 * 20900, about, sequence calculation, three-dimensional structure analysis of DspA-Te, the subunits forming the pores at the ferritin-like interfaces have a slightly different orientation with respect to the three-fold symmetry axes than in the other Dps structures, overview. DpsA-Te ferroxidase center is unique, owing to the presence of a His78 in place of the canonical Asp metal ligand | Thermosynechococcus vestitus |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
4 Fe2+ + 4 H+ + O2 | Thermosynechococcus vestitus | - |
4 Fe3+ + 2 H2O | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Thermosynechococcus vestitus | Q8DL82 | two Dps proteins, DpsA-Te and Dps-Te, encoded by the two genes tll2470 and tll0614 or dpsA-Te and dps-Te, respectively | - |
Purification (Comment) | Organism |
---|---|
recombinant His-tagged protein from Escherichia coli strain BL21(DE3) by heat treatment at 75°C for 10 min, dialysis, anion exchange chromatography, and affinity chromatography, followed by cleavage of the His-tag | Thermosynechococcus vestitus |
Reaction | Comment | Organism | Reaction ID |
---|---|---|---|
4 Fe(II) + 4 H+ + O2 = 4 Fe(III) + 2 H2O | reaction mechanism, overview. Two reaction steps: 1. 2 Fe2+ O2 + 2 H+ = 2 Fe3+ + H2O2 and 2. H2O2 + 2 Fe2+ + 2 H+ = 2 Fe3+ + 2 H2O. The second step is rate-limiting | Thermosynechococcus vestitus |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
4 Fe2+ + 4 H+ + O2 | - |
Thermosynechococcus vestitus | 4 Fe3+ + 2 H2O | - |
? |
Subunits | Comment | Organism |
---|---|---|
dodecamer | 12 * 20900, about, sequence calculation, three-dimensional structure analysis of DspA-Te, the subunits forming the pores at the ferritin-like interfaces have a slightly different orientation with respect to the three-fold symmetry axes than in the other Dps structures, overview. DpsA-Te ferroxidase center is unique, owing to the presence of a His78 in place of the canonical Asp metal ligand | Thermosynechococcus vestitus |
Synonyms | Comment | Organism |
---|---|---|
Dps-Te | - |
Thermosynechococcus vestitus |
DpsA | - |
Thermosynechococcus vestitus |
DpsA-Te | - |
Thermosynechococcus vestitus |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
20 | - |
standard assay at | Thermosynechococcus vestitus |
Temperature Minimum [°C] | Temperature Maximum [°C] | Comment | Organism |
---|---|---|---|
10 | 50 | assay range | Thermosynechococcus vestitus |
Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|
100 | - |
completely stable at pH 3.0-7.0, but complete and irreversibe degeneration at 75-80°C | Thermosynechococcus vestitus |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7 | - |
assay at | Thermosynechococcus vestitus |
pH Stability | pH Stability Maximum | Comment | Organism |
---|---|---|---|
2 | 7 | at pH 2.0, the enzyme structure is stable at room temperature, but completely and irreversibly degenerates at 75-80°C | Thermosynechococcus vestitus |
General Information | Comment | Organism |
---|---|---|
additional information | DpsA-Te ows a unique substitution of a metal ligand at the A-site, i.e. His78 in place of the canonical Asp, and a His164 in place of a hydrophobic residue at a metal-coordinating distance in the B-site. In contrast to the typical behavior of Dps proteins, where Fe2+ oxidation by H2O2 is about 100fold faster than by O2, in DpsA-Te the ferroxidation efficiency of O2 is very high and resembles that of H2O2. DpsA-Te contains two Zn2+ bound at the ferroxidase center. The latter Zn2+ is displaced by incoming iron, such that Zn(II)-Fe(III) complexes are formed upon oxidation | Thermosynechococcus vestitus |
physiological function | DpsA-Te can protect DNA molecules against Fe(II)-mediated and H2O2-mediated damage. Dps-Te and DpsA-Te, together with ferritin, play an important role in alleviating the toxic effects of reactive oxygen species, physiological basis of the coexistence of two Dps proteins in the organism, overview | Thermosynechococcus vestitus |