2c2u
From Proteopedia
DPS FROM DEINOCOCCUS RADIODURANS
Structural highlights
Function[DPS1_DEIRA] 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). Both oligomeric forms of dps exhibit ferroxidase activity and DNA binding. Dodecameric dps is capable of Fe(2+) oxidation/mineralization. Only dimeric dps affords efficient DNA protection against hydroxyl radical-mediated cleavage.[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 crystal structure of a DNA-binding protein from starved cells (Dps) (DR2263) from Deinococcus radiodurans was determined in two states: a native form, to 1.1-A resolution, and one soaked in an iron solution, to 1.6-A resolution. In comparison with other Dps proteins, DR2263 has an extended N-terminal extension, in both structures presented here, a novel metal binding site was identified in this N-terminal extension and was assigned to bound zinc. The zinc is tetrahedrally coordinated and the ligands, that belong to the N-terminal extension, are two histidines, one glutamate and one aspartate residue, which are unique to this protein within the Dps family. In the iron-soaked crystal structure, a total of three iron sites per monomer were found: one site corresponds to the ferroxidase centre with structural similarities to those found in other Dps family members; the two other sites are located on the two different threefold axes corresponding to small pores in the Dps sphere, which may possibly form the entrance and exit channels for iron storage. The crystal structure of Deinococcus radiodurans Dps protein (DR2263) reveals the presence of a novel metal centre in the N terminus.,Romao CV, Mitchell EP, McSweeney S J Biol Inorg Chem. 2006 Oct;11(7):891-902. Epub 2006 Jul 20. PMID:16855817[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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