Iron-oxo clusters biomineralizing on protein surfaces: structural analysis of Halobacterium salinarum DpsA in its low- and high-iron states.

ABSTRACT: The crystal structure of the Dps-like (Dps, DNA-protecting protein during starvation) ferritin protein DpsA from the halophile Halobacterium salinarum was determined with low endogenous iron content at 1.6-A resolution. The mechanism of iron uptake and storage was analyzed in this noncanonical ferritin by three high-resolution structures at successively increasing iron contents. In the high-iron state of the DpsA protein, up to 110 iron atoms were localized in the dodecameric protein complex. For ultimate iron storage, the archaeal ferritin shell comprises iron-binding sites for iron translocation, oxidation, and nucleation. Initial iron-protein interactions occur through acidic residues exposed along the outer surface in proximity to the iron entry pore. This narrow pore permits transloca

SUBMITTER: Zeth K 

PROVIDER: S-EPMC518833 | biostudies-literature | 2004 Sep

REPOSITORIES: biostudies-literature