View source for 1fck


==STRUCTURE OF DICERIC HUMAN LACTOFERRIN==
<StructureSection load='1fck' size='340' side='right'caption='[[1fck]], [[Resolution|resolution]] 2.20&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1fck]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1FCK OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1FCK FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CE:CERIUM+(III)+ION'>CE</scene>, <scene name='pdbligand=CO3:CARBONATE+ION'>CO3</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1lfg|1lfg]], [[1cb6|1cb6]], [[1lfi|1lfi]], [[1lct|1lct]]</div></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=1fck FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1fck OCA], [https://pdbe.org/1fck PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1fck RCSB], [https://www.ebi.ac.uk/pdbsum/1fck PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1fck ProSAT]</span></td></tr>
</table>
== Function ==
[[https://www.uniprot.org/uniprot/TRFL_HUMAN TRFL_HUMAN]] Transferrins are iron binding transport proteins which can bind two Fe(3+) ions in association with the binding of an anion, usually bicarbonate.<ref>PMID:12535064</ref> <ref>PMID:22320386</ref>   Lactotransferrin has antimicrobial activity which depends on the extracellular cation concentration.<ref>PMID:12535064</ref> <ref>PMID:22320386</ref>   Lactoferroxins A, B and C have opioid antagonist activity. Lactoferroxin A shows preference for mu-receptors, while lactoferroxin B and C have somewhat higher degrees of preference for kappa-receptors than for mu-receptors.<ref>PMID:12535064</ref> <ref>PMID:22320386</ref>   The lactotransferrin transferrin-like domain 1 functions as a serine protease of the peptidase S60 family that cuts arginine rich regions. This function contributes to the antimicrobial activity.<ref>PMID:12535064</ref> <ref>PMID:22320386</ref>   Isoform DeltaLf: transcription factor with antiproliferative properties and inducing cell cycle arrest. Binds to DeltaLf response element found in the SKP1, BAX, DCPS, and SELH promoters.<ref>PMID:12535064</ref> <ref>PMID:22320386</ref>  
== 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/fc/1fck_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=1fck ConSurf].
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== Publication Abstract from PubMed ==
Proteins of the transferrin family play a key role in iron homeostasis through their extremely strong binding of iron, as Fe3+. They are nevertheless able to bind a surprisingly wide variety of other metal ions. To investigate how metal ions of different size, charge and coordination characteristics are accommodated, we have determined the crystal structure of human lactoferrin (Lf) complexed with Ce4+. The structure, refined at 2.2 A resolution (R=20.2%, Rfree=25.7%) shows that the two Ce4+ ions occupy essentially the same positions as do Fe3+, and that the overall protein structure is unchanged; the same closed structure is formed for Ce2Lf as for Fe2Lf. The larger metal ion is accommodated by small shifts in the protein ligands, made possible by the presence of water molecules adjacent to each binding site. The two Ce4+ sites are equally occupied, indicating that the known difference in the pH-dependent release of Ce4+ arises from a specific protonation event, possibly of the His ligand in one of the binding sites. Comparing the effects of binding Ce4+ with those for the binding of other metal ions, we conclude that the ability of transferrins to accommodate metal ions other than Fe3+ depends on an interplay of charge, size, coordination and geometrical preferences of the bound metal ion. However, it is the ability to accept the six-coordinate, approximately octahedral, site provided by the protein that is of greatest importance.

Metal substitution in transferrins: specific binding of cerium(IV) revealed by the crystal structure of cerium-substituted human lactoferrin.,Baker HM, Baker CJ, Smith CA, Baker EN J Biol Inorg Chem. 2000 Dec;5(6):692-8. PMID:11128996<ref>PMID:11128996</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 1fck" style="background-color:#fffaf0;"></div>

==See Also==
*[[Lactoferrin|Lactoferrin]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Baker, C J]]
[[Category: Baker, E N]]
[[Category: Baker, H M]]
[[Category: Smith, C A]]
[[Category: Cerium]]
[[Category: Lanthanide]]
[[Category: Metal transport]]
[[Category: Metal-binding]]
[[Category: Transferrin]]