View source for 3ka4


==Frog M-ferritin with cobalt==
<StructureSection load='3ka4' size='340' side='right'caption='[[3ka4]], [[Resolution|resolution]] 1.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3ka4]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Lithobates_catesbeianus Lithobates catesbeianus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3KA4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3KA4 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]] 1.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=CO:COBALT+(II)+ION'>CO</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=3ka4 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3ka4 OCA], [https://pdbe.org/3ka4 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3ka4 RCSB], [https://www.ebi.ac.uk/pdbsum/3ka4 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3ka4 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/FRI2_LITCT FRI2_LITCT] Stores iron in a soluble, non-toxic, readily available form. Important for iron homeostasis. Has ferroxidase activity. Iron is taken up in the ferrous form and deposited as ferric hydroxides after oxidation.
== 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/ka/3ka4_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/main_output.php?pdb_ID=3ka4 ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Ferritin nanocages synthesize ferric oxide minerals, containing hundreds to thousands of Fe(III) diferric oxo/hydroxo complexes, by reactions of Fe(II) ions with O(2) at multiple di-iron catalytic centers. Ferric-oxy multimers, tetramers, and/or larger mineral nuclei form during postcatalytic transit through the protein cage, and mineral accretion occurs in the central cavity. We determined how Fe(II) substrates can access catalytic sites using frog M ferritins, active and inactivated by ligand substitution, crystallized with 2.0 M Mg(II) +/- 0.1 M Co(II) for Co(II)-selective sites. Co(II) inhibited Fe(II) oxidation. High-resolution (&lt;1.5 A) crystal structures show (1) a line of metal ions, 15 A long, which penetrates the cage and defines ion channels and internal pores to the nanocavity that link external pores to the cage interior, (2) metal ions near negatively charged residues at the channel exits and along the inner cavity surface that model Fe(II) transit to active sites, and (3) alternate side-chain conformations, absent in ferritins with catalysis eliminated by amino acid substitution, which support current models of protein dynamics and explain changes in Fe-Fe distances observed during catalysis. The new structural data identify a approximately 27-A path Fe(II) ions can follow through ferritin entry channels between external pores and the central cavity and along the cavity surface to the active sites where mineral synthesis begins. This "bucket brigade" for Fe(II) ion access to the ferritin catalytic sites not only increases understanding of biological nanomineral synthesis but also reveals unexpected design principles for protein cage-based catalysts and nanomaterials.

Moving metal ions through ferritin-protein nanocages from three-fold pores to catalytic sites.,Tosha T, Ng HL, Bhattasali O, Alber T, Theil EC J Am Chem Soc. 2010 Oct 20;132(41):14562-9. PMID:20866049<ref>PMID:20866049</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3ka4" style="background-color:#fffaf0;"></div>

==See Also==
*[[Ferritin 3D structures|Ferritin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Lithobates catesbeianus]]
[[Category: Alber T]]
[[Category: Bhattasali O]]
[[Category: Ng HL]]
[[Category: Theil E]]
[[Category: Tosha T]]