The DpsA-homologue of the archaeon Halobacterium salinarum is a ferritin

Reindel, Sabine; Anemüller, Stefan; Sawaryn, A.; Matzanke, Berthold F.

doi:10.1016/s0167-4838(02)00361-8

Cited by 24 publications

(29 citation statements)

References 33 publications

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“…Overall, the iron sites can be subdivided into four classes according to their locations and presumptive function in the DpsA complex (see also Table 1): (i) iron access route (three subsites T1-T3 in FE30 and FE120); (ii) the ferroxidase center FOC (three subsites F1-F3 in FE30, F1 in FE120); (iii) nucleation center NI (three subsites, N11-N13 in FE30 and FE120; N11 and N13 are symmetry related); (iv) nucleation center NII (five subsites, N21-N25, in FE30 and FE120, N22, N23, and N24 are related by symmetry). It is noteworthy that the overall numbers agree quite well with the amount of bound iron determined in isolated samples of DpsA (23).…”

Section: Structural Comparison Of Dpsa With 24-mer Ferritins and Dps-supporting

confidence: 77%

“…One of them was the archaeal ferritin DpsA protein (ref. 23; 182 aa, M r ϭ 20,100), which was crystallized in the trigonal crystal forms P3 1 21 (crystal form A) and P321 (crystal form B) by using polyethylene glycol 400 as a precipitant.…”

Section: Resultsmentioning

confidence: 99%

“…Because the haloarchaeon H. salinarum is an aerobic chemoorganotrophically growing organism (31), the function of DpsA, iron storage and protection again reactive oxygen species, presumably resembles its eubacterial relatives. Iron storage, the hallmark of ferritins, was recently described for DpsA (23), whereas direct binding to DNA that is exerted by Dps-like ferritins from E. coli and a few other eubacteria could not yet be demonstrated for DpsA.…”

Section: Structural Comparison Of Dpsa With 24-mer Ferritins and Dps-mentioning

confidence: 99%

“…Recently, DpsA of H. salinarum was shown to complex up to 100 iron atoms per dodecamer, which are at least partly constituents of large ferric iron clusters according to EPR spectroscopy (23). To locate iron-binding sites still missing in the native structure of H. salinarum DpsA, we incubated crystals for 30 (FE30) and 120 min (FE120) with Fe 2ϩ under conditions that may promote biomineralization.…”

Section: Structural Comparison Of Dpsa With 24-mer Ferritins and Dps-mentioning

confidence: 99%

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

Zeth

Offermann

Essen

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

108

122

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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-Å resolution. The mechanism of iron uptake and storage was analyzed in this noncanonical ferritin by three highresolution 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 translocation of ions toward the ferroxidase centers via two discrete steps. Iron oxidation proceeds by transient formation of tri-iron ferroxidase centers. Iron storage by biomineralization inside the ferritin shell occurs at two iron nucleation centers. Here, a single iron atom provides a structural seed for iron-oxide cluster formation. The clusters with up to five iron atoms adopt a geometry that is different from natural biominerals like magnetite but resembles iron clusters so far known only from bioinorganic model compounds.ferritin ͉ iron-binding ͉ inorganic cluster formation ͉ x-ray crystal structure

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Section: Structural Comparison Of Dpsa With 24-mer Ferritins and Dps-supporting

confidence: 77%

Section: Resultsmentioning

confidence: 99%

Section: Structural Comparison Of Dpsa With 24-mer Ferritins and Dps-mentioning

confidence: 99%

Section: Structural Comparison Of Dpsa With 24-mer Ferritins and Dps-mentioning

confidence: 99%

See 2 more Smart Citations

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

Zeth

Offermann

Essen

et al. 2004

Proc. Natl. Acad. Sci. U.S.A.

108

122

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“…These suggestions have recently been corroborated by N-terminal deletion mutants of E. coli Dps that do not bind DNA (38). Multiple sequence alignments identify basic residues in extended N-terminal domains of both the SsDps and in the Dps-like protein from H. salinarum, suggesting their role in DNA association (35,39,40). A short C-terminal extension of the SsDps protein also contains three basic amino acids that may also play a role in DNA binding (Fig.…”

Section: Resultsmentioning

confidence: 75%

An archaeal antioxidant: Characterization of a Dps-like protein from Sulfolobus solfataricus

Wiedenheft

Mosolf

Willits

et al. 2005

Proc. Natl. Acad. Sci. U.S.A.

107

110

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Evolution of an oxygenic atmosphere required primordial life to accommodate the toxicity associated with reactive oxygen species. We have characterized an archaeal antioxidant from the hyperthermophilic acidophile Sulfolobus solfataricus. The amino acid sequence of this Ϸ22-kDa protein shares little sequence similarity with proteins with known function. However, the protein shares high sequence similarity with hypothetical proteins in other archaeal and bacterial genomes. Nine of these hypothetical proteins form a monophyletic cluster within the broad superfamily of ferritin-like diiron-carboxylate proteins. Higher order structural predictions and image reconstructions indicate that the S. solfataricus protein is structurally related to a class of DNA-binding protein from starved cells (Dps). The recombinant protein self assembles into a hollow dodecameric protein cage having tetrahedral symmetry (SsDps). The outer shell diameter is Ϸ10 nm, and the interior diameter is Ϸ5 nm. Dps proteins have been shown to protect nucleic acids by physically shielding DNA against oxidative damage and by consuming constituents involved in Fenton chemistry. In vitro, the assembled archaeal protein efficiently uses H2O2 to oxidize Fe(II) to Fe(III) and stores the oxide as a mineral core on the interior surface of the protein cage. The ssdps gene is upregulated in S. solfataricus cultures grown in iron-depleted media and upon H2O2 stress, but is not induced by other stresses. SsDps-mediated reduction of hydrogen peroxide and possible DNA-binding capabilities of this archaeal Dps protein are mechanisms by which S. solfataricus mitigates oxidative damage.ferritin ͉ iron ͉ oxidative stress ͉ biomineralization ͉ hyperthermophile

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