View source for 4xku


==E coli BFR variant Y114F==
<StructureSection load='4xku' size='340' side='right'caption='[[4xku]], [[Resolution|resolution]] 1.78&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4xku]] is a 12 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli_K-12 Escherichia coli K-12]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4XKU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4XKU FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.78&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=4xku FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4xku OCA], [https://pdbe.org/4xku PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4xku RCSB], [https://www.ebi.ac.uk/pdbsum/4xku PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4xku ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/BFR_ECOLI 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.<ref>PMID:10769150</ref> <ref>PMID:14636073</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Ferritins are iron storage proteins that overcome the problems of toxicity and poor bioavailability of iron by catalyzing iron oxidation and mineralization through the activity of a diiron ferroxidase site. Unlike in other ferritins, the oxidized di-Fe3+ site of Escherichia coli bacterioferritin (EcBFR) is stable and therefore does not function as a conduit for the transfer of Fe3+ into the storage cavity, but instead acts as a true catalytic cofactor that cycles its oxidation state while driving Fe2+ oxidation in the cavity. Herein, we demonstrate that EcBFR mineralization depends on three aromatic residues near the diiron site, Tyr25, Tyr58, and Trp133, and that a transient radical is formed on Tyr25. The data indicate that the aromatic residues, together with a previously identified inner surface iron site, promote mineralization by ensuring the simultaneous delivery of two electrons, derived from Fe2+ oxidation in the BFR cavity, to the di-ferric catalytic site for safe reduction of O2 .

Three Aromatic Residues are Required for Electron Transfer during Iron Mineralization in Bacterioferritin.,Bradley JM, Svistunenko DA, Lawson TL, Hemmings AM, Moore GR, Le Brun NE Angew Chem Int Ed Engl. 2015 Oct 16. doi: 10.1002/anie.201507486. PMID:26474305<ref>PMID:26474305</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4xku" style="background-color:#fffaf0;"></div>

==See Also==
*[[Ferritin 3D structures|Ferritin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli K-12]]
[[Category: Large Structures]]
[[Category: Bradley JM]]
[[Category: Hemmings AM]]
[[Category: Le Brun NE]]