PMID:12163499

From EcoliWiki
Jump to navigation Jump to search
Citation

Ilari, A, Ceci, P, Ferrari, D, Rossi, GL and Chiancone, E (2002) Iron incorporation into Escherichia coli Dps gives rise to a ferritin-like microcrystalline core. J. Biol. Chem. 277:37619-23

Abstract

Escherichia coli Dps belongs to a family of bacterial stress-induced proteins to protect DNA from oxidative damage. It shares with Listeria innocua ferritin several structural features, such as the quaternary assemblage and the presence of an unusual ferroxidase center. Indeed, it was recently recognized to be able to oxidize and incorporate iron. Since ferritins are endowed with the unique capacity to direct iron deposition toward formation of a microcrystalline core, the structure of iron deposited in the E. coli Dps cavity was studied. Polarized single crystal absorption microspectrophotometry of iron-loaded Dps shows that iron ions are oriented. The spectral properties in the high spin 3d(5) configuration point to a crystal form with tetrahedral symmetry where the tetrahedron center is occupied by iron ions and the vertices by oxygen. Crystals of iron-loaded Dps also show that, as in mammalian ferritins, iron does not remain bound to the site after oxidation has taken place. The kinetics of the iron reduction/release process induced by dithionite were measured in the crystal and in solution. The reaction appears to have two phases, with t(12) of a few seconds and several minutes at neutral pH values, as in canonical ferritins. This behavior is attributed to a similar composition of the iron core.

Links

PubMed Online version:10.1074/jbc.M206186200

Keywords

Bacterial Proteins/chemistry; Bacterial Proteins/metabolism; Ceruloplasmin/chemistry; Ceruloplasmin/metabolism; Crystallization; DNA-Binding Proteins/chemistry; DNA-Binding Proteins/metabolism; Dithionite/metabolism; Escherichia coli/metabolism; Ferritins/chemistry; Iron/metabolism; Kinetics; Protein Structure, Quaternary; Spectrophotometry

Significance

You can help EcoliWiki by summarizing why this paper is useful

Useful Materials and Methods

You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.

Annotations

<annotationlinks/>

EcoliWiki Links

Add links to pages that link here (e.g. gene, product, method pages)

References

See Help:References for how to manage references in EcoliWiki.