View source for 3u0d

==The structure of human Siderocalin bound to the bacterial siderophore 2,3-DHBA==
<StructureSection load='3u0d' size='340' side='right' caption='[[3u0d]], [[Resolution|resolution]] 2.51&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3u0d]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3U0D OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3U0D FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=DBH:2,3-DIHYDROXY-BENZOIC+ACID'>DBH</scene>, <scene name='pdbligand=FE:FE+(III)+ION'>FE</scene></td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">LCN2, HNL, NGAL ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=9606 Homo sapiens])</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3u0d FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3u0d OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3u0d RCSB], [http://www.ebi.ac.uk/pdbsum/3u0d PDBsum]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/NGAL_HUMAN NGAL_HUMAN]] Iron-trafficking protein involved in multiple processes such as apoptosis, innate immunity and renal development. Binds iron through association with 2,5-dihydroxybenzoic acid (2,5-DHBA), a siderophore that shares structural similarities with bacterial enterobactin, and delivers or removes iron from the cell, depending on the context. Iron-bound form (holo-24p3) is internalized following binding to the SLC22A17 (24p3R) receptor, leading to release of iron and subsequent increase of intracellular iron concentration. In contrast, association of the iron-free form (apo-24p3) with the SLC22A17 (24p3R) receptor is followed by association with an intracellular siderophore, iron chelation and iron transfer to the extracellular medium, thereby reducing intracellular iron concentration. Involved in apoptosis due to interleukin-3 (IL3) deprivation: iron-loaded form increases intracellular iron concentration without promoting apoptosis, while iron-free form decreases intracellular iron levels, inducing expression of the proapoptotic protein BCL2L11/BIM, resulting in apoptosis. Involved in innate immunity, possibly by sequestrating iron, leading to limit bacterial growth.<ref>PMID:12453413</ref>  
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Siderocalin (also lipocalin 2, NGAL or 24p3) binds iron as complexes with specific siderophores, which are low molecular weight, ferric ion-specific chelators. In innate immunity, siderocalin slows the growth of infecting bacteria by sequestering bacterial ferric siderophores. Siderocalin also binds simple catechols, which can serve as siderophores in the damaged urinary tract. Siderocalin has also been proposed to alter cellular iron trafficking, for instance, driving apoptosis through iron efflux via BOCT. An endogenous siderophore composed of gentisic acid (2,5-dihydroxybenzoic acid) substituents was proposed to mediate cellular efflux. However, binding studies reported herein contradict the proposal that gentisic acid forms high-affinity ternary complexes with siderocalin and iron, or that gentisic acid can serve as an endogenous siderophore at neutral pH. We also demonstrate that siderocalin does not induce cellular iron efflux or stimulate apoptosis, questioning the role siderocalin plays in modulating iron metabolism.

Siderocalin/Lcn2/NGAL/24p3 does not drive apoptosis through gentisic acid mediated iron withdrawal in hematopoietic cell lines.,Correnti C, Richardson V, Sia AK, Bandaranayake AD, Ruiz M, Suryo Rahmanto Y, Kovacevic Z, Clifton MC, Holmes MA, Kaiser BK, Barasch J, Raymond KN, Richardson DR, Strong RK PLoS One. 2012;7(8):e43696. doi: 10.1371/journal.pone.0043696. Epub 2012 Aug 21. PMID:22928018<ref>PMID:22928018</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>

==See Also==
*[[Neutrophil gelatinase-associated lipocalin|Neutrophil gelatinase-associated lipocalin]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Structural genomic]]
[[Category: Antimicrobial protein]]
[[Category: Beta-barrel]]
[[Category: Siderophore]]
[[Category: Ssgcid]]
[[Category: Transport protein]]