EC Number   |
General Information |
Reference |
|---|
   1.16.3.2 | evolution |
Dps (DNA-binding protein from starved cells) belongs to a subfamily of ferritins. The presence of a ferroxidase centre, composed of highly conserved residues, is a signature of this protein family |
-, 745726 |
| 1.16.3.2 | evolution |
the ferritin (Ftn) and bacterioferritin (Bfr) proteins of the ferritin-like superfamily constitute a prime example of a remarkable combination of evolutionary conserved iron uptake and release processes that are integrated with a variety in iron translocation mechanisms. Ftns and Bfrs have a highly conserved architecture |
745442 |
| 1.16.3.2 | more |
iron mineralization kinetics |
745693 |
| 1.16.3.2 | more |
role for His54 as a metal ion trap that maintains the correct levels of access of iron to the active site. His54 binding to iron(II) and other divalent cations, with its imidazole ring proposed as gate that influences iron movement to/from the active site. |
744403 |
| 1.16.3.2 | more |
two conserved histidine residues, H25 and H37, located at the ferroxidase centre of the Campylobacter jejuni Dps (DNA-binding protein from starved cells) protein, are not strictly required for metal binding and oxidation. The archetypical function of Dps seems to be DNA protection against hydroxyl radicals that are produced when Fe2+ and H2O2 combine |
-, 745726 |
| 1.16.3.2 | physiological function |
Dps proteins are widely distributed in being required for survival during stressful conditions such as nutrient starvation, thermal stress and oxidative conditions, and inside biofilm. Campylobacter jejuni needs to be able to counteract various types of environmental stress during colonization, for example extreme pH and low availability of trace metals such as iron. Dps proteins can store iron atoms inside the dodecamer. Campylobacter jejuni Dps is able to bind DNA, and the DNA-binding activity is stimulated by Fe2+ (at room temperature in Bis-Tris, pH 6.0), overview |
-, 745726 |
| 1.16.3.2 | physiological function |
ferritin and ferritin-like molecules (Bfr and bacterial Ftn) are supramolecular assemblies built from 24 subunits into a nearly spherical architecture with a hollow core where up to 4000 iron ions can be stored as a ferric mineral that is protected from indiscriminant cellular reducing agents. The enzymes possess an integrated ferroxidase activity, EC 1.16.3.1. . Network-weaving algorithm that passes threads of an allosteric network through highly correlated residues using hierarchical clustering, the residue-residue correlations are calculated, modeling, overview. The ferritin structures evolved in a way to limit the influence of functionally unrelated events in the cytoplasm on the allosteric network to maintain stability of the translocation mechanisms. Diversity in mechanisms of iron traffic, overview. It is thought that iron translocation across the ferritin shell requires cooperative motions of residues aligning the path. In the process of iron capture and storage, iron traverses from the ferritin exterior surface to the interior cavity via a ferroxidase center, where soluble Fe2+ is oxidized to Fe3+. A ferroxidase center is located in the middle of each subunit in the heavy (H)-type and M-type subunits of eukaryotic Ftns. Release of iron from the ferritin cavity requires reduction of ferric iron in the interior ferritin cavity and egress of ferrous ions via pores in the protein shell. The networks in BfrB and FtnA connect the ferroxidase center with the 4fold pores and B-pores, leaving the 3fold pores unengaged |
745442 |
| 1.16.3.2 | physiological function |
ferritin and ferritin-like molecules (Bfr and bacterial Ftn) are supramolecular assemblies built from 24 subunits into a nearly spherical architecture with a hollow core where up to 4000 iron ions can be stored as a ferric mineral that is protected from indiscriminant cellular reducing agents. The enzymes possess an integrated ferroxidase activity, EC 1.16.3.1. Network-weaving algorithm that passes threads of an allosteric network through highly correlated residues using hierarchical clustering, the residue-residue correlations are calculated, modeling, overview. Each type of ferritin-like molecule has an extended network of highly correlated residues, connecting distant pores and the ferroxidase center. The ferritin structures evolved in a way to limit the influence of functionally unrelated events in the cytoplasm on the allosteric network to maintain stability of the translocation mechanisms. Diversity in mechanisms of iron traffic, overview. It is thought that iron translocation across the ferritin shell requires cooperative motions of residues aligning the path. In the process of iron capture and storage, iron traverses from the ferritin exterior surface to the interior cavity via a ferroxidase center, where soluble Fe2+ is oxidized to Fe3+. A ferroxidase center is located in the middle of each subunit in Bfrs. Release of iron from the ferritin cavity requires reduction of ferric iron in the interior ferritin cavity and egress of ferrous ions via pores in the protein shell. The networks in BfrB and FtnA connect the ferroxidase center with the 4fold pores and B-pores, leaving the 3fold pores unengaged |
745442 |
| 1.16.3.2 | physiological function |
ferritins use Fe2+ and either dioxygen or hydrogen peroxide as oxidants to form a hydrous ferric oxide mineral core. The enzyme EcFtnA displays H2O2 detoxification properties whereby two Fe2+ are oxidized per H2O2 reduced. The enzyme requires fully functional A- and B-sites for high ferroxidase activity. The mechanism of iron oxidation and deposition in EcFtnA is complex with multiple reactions involving the A-, B-, and C-sites of the ferroxidase center, the mineral surface and both O2 and H2O2 as oxidants |
744322 |
| 1.16.3.2 | physiological function |
the major iron-storage protein ferritin A in Escherichia coli acts as an iron buffer for re-assembly of iron-sulfur clusters in response to hydrogen peroxide stress. The iron stored in ferritin A can be retrieved by an iron chaperon IscA for the re-assembly of the iron-sulfur cluster in a proposed scaffold IscU in the presence of the thioredoxin reductase system which emulates normal intracellular redox potential |
729363 |
