3e1j: Difference between revisions
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[[Image: | ==Crystal structure of E. coli Bacterioferritin (BFR) with an unoccupied ferroxidase centre (APO-BFR).== | ||
<StructureSection load='3e1j' size='340' side='right' caption='[[3e1j]], [[Resolution|resolution]] 2.70Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3e1j]] is a 12 chain structure with sequence from [http://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=3E1J OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3E1J FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=HEM:PROTOPORPHYRIN+IX+CONTAINING+FE'>HEM</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene><br> | |||
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3e1l|3e1l]], [[3e1m|3e1m]], [[3e1n|3e1n]], [[3e1o|3e1o]], [[3e1p|3e1p]], [[3e1q|3e1q]]</td></tr> | |||
<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">bfr, b3336, JW3298 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=83333 Escherichia coli K-12])</td></tr> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3e1j FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3e1j OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3e1j RCSB], [http://www.ebi.ac.uk/pdbsum/3e1j PDBsum]</span></td></tr> | |||
<table> | |||
== Evolutionary Conservation == | |||
[[Image:Consurf_key_small.gif|200px|right]] | |||
Check<jmol> | |||
<jmolCheckbox> | |||
<scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/e1/3e1j_consurf.spt"</scriptWhenChecked> | |||
<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | |||
<text>to colour the structure by Evolutionary Conservation</text> | |||
</jmolCheckbox> | |||
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/chain_selection.php?pdb_ID=2ata ConSurf]. | |||
<div style="clear:both"></div> | |||
<div style="background-color:#fffaf0;"> | |||
== 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<ref>PMID:19391621</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
==See Also== | ==See Also== | ||
*[[Ferritin|Ferritin]] | *[[Ferritin|Ferritin]] | ||
== References == | |||
== | <references/> | ||
< | __TOC__ | ||
</StructureSection> | |||
[[Category: Escherichia coli k-12]] | [[Category: Escherichia coli k-12]] | ||
[[Category: Brun, N Le.]] | [[Category: Brun, N Le.]] | ||
Revision as of 15:13, 29 September 2014
Crystal structure of E. coli Bacterioferritin (BFR) with an unoccupied ferroxidase centre (APO-BFR).Crystal structure of E. coli Bacterioferritin (BFR) with an unoccupied ferroxidase centre (APO-BFR).
Structural highlights
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 PubMedFerritin 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[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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