3e1n

Crystal structure of E. coli Bacterioferritin (BFR) after a 65 minute (aerobic) exposure to FE(II) revealing a possible MU-OXO bridge/MU-Hydroxy bridged DIIRON intermediate at the ferroxidase centre. (FE(III)-O-FE(III)-BFR).

spinqualitylabelsall models 3e1n, resolution 2.80Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 3e1n is a 12 chain structure with sequence from Ecoli. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: FE2, HEM, SO4, UNK Related: 3e1j, 3e1l, 3e1m, 3e1o, 3e1p, 3e1q Gene: BFR (ECOLI) Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function [BFR_ECOLI] Iron-storage protein, whose ferroxidase center binds Fe(2+) ions, oxidizes them by dioxygen to Fe(3+), and participates in the subsequent Fe(3+) oxide mineral core formation within the central cavity of the protein complex. The mineralized iron core can contain as many as 2700 iron atoms/24-meric molecule. 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 PubMed Ferritin proteins function to detoxify, solubilize and store cellular iron by directing the synthesis of a ferric oxyhydroxide mineral solubilized within the protein's central cavity. Here, through the application of X-ray crystallographic and kinetic methods, we report significant new insight into the mechanism of mineralization in a bacterioferritin (BFR). The structures of nonheme iron-free and di-Fe(2+) forms of BFR showed that the intrasubunit catalytic center, known as the ferroxidase center, is preformed, ready to accept Fe(2+) ions with little or no reorganization. Oxidation of the di-Fe(2+) center resulted in a di-Fe(3+) center, with bridging electron density consistent with a mu-oxo or hydro bridged species. The mu-oxo bridged di-Fe(3+) center appears to be stable, and there is no evidence that Fe(3+)species are transferred into the core from the ferroxidase center. Most significantly, the data also revealed a novel Fe(2+) binding site on the inner surface of the protein, lying approximately 10 A directly below the ferroxidase center, coordinated by only two residues, His46 and Asp50. Kinetic studies of variants containing substitutions of these residues showed that the site is functionally important. In combination, the data support a model in which the ferroxidase center functions as a true catalytic cofactor, rather than as a pore for the transfer of iron into the central cavity, as found for eukaryotic ferritins. The inner surface iron site appears to be important for the transfer of electrons, derived from Fe(2+) oxidation in the cavity, to the ferroxidase center. Bacterioferritin may represent an evolutionary link between ferritins and class II di-iron proteins not involved in iron metabolism. Structural basis for iron mineralization by bacterioferritin.,Crow A, Lawson TL, Lewin A, Moore GR, Le Brun NE J Am Chem Soc. 2009 May 20;131(19):6808-13. PMID:19391621 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Ferritin

Proteopedia Page Contributors and Editors (what is this?)

OCA