Structural highlights
Function[DPS_SULSO] Protects DNA from oxidative damage by sequestering intracellular Fe(2+) ion and storing it in the form of Fe(3+) oxyhydroxide mineral. One hydrogen peroxide oxidizes two Fe(2+) ions, which prevents hydroxyl radical production by the Fenton reaction (By similarity). In vitro, it efficiently oxidizes Fe(2+) in the presence of hydrogen peroxide and stores it as a mineral core.[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe superfamily of ferritin-like proteins has recently expanded to include a phylogenetically distinct class of proteins termed DPS-like (DPSL) proteins. Despite their distinct genetic signatures, members of this subclass share considerable similarity to previously recognized DPS proteins. Like DPS, these proteins are expressed in response to oxidative stress, form dodecameric cage-like particles, preferentially utilize H(2)O(2) in the controlled oxidation of Fe(2+), and possess a short N-terminal extension implicated in stabilizing cellular DNA. Given these extensive similarities, the functional properties responsible for the preservation of the DPSL signature in the genomes of diverse prokaryotes have been unclear. Here, we describe the crystal structure of a DPSL protein from the thermoacidophilic archaeon Sulfolobus solfataricus. Although the overall fold of the polypeptide chain and the oligomeric state of this protein are indistinguishable from those of authentic DPS proteins, several important differences are observed. First, rather than a ferroxidase site at the subunit interface, as is observed in all other DPS proteins, the ferroxidase site in SsDPSL is buried within the four-helix bundle, similar to bacterioferritin. Second, the structure reveals a channel leading from the exterior surface of SsDPSL to the bacterioferritin-like dimetal binding site, possibly allowing divalent cations and/or H(2)O(2) to access the active site. Third, a pair of cysteine residues unique to DPSL proteins is found adjacent to the dimetal binding site juxtaposed between the exterior surface of the protein and the active site channel. The cysteine residues in this thioferritin motif may play a redox active role, possibly serving to recycle iron at the ferroxidase center. Structure of the DPS-like protein from Sulfolobus solfataricus reveals a bacterioferritin-like dimetal binding site within a DPS-like dodecameric assembly.,Gauss GH, Benas P, Wiedenheft B, Young M, Douglas T, Lawrence CM Biochemistry. 2006 Sep 12;45(36):10815-27. PMID:16953567[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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