View source for 1qqs

==NEUTROPHIL GELATINASE ASSOCIATED LIPOCALIN HOMODIMER==
<StructureSection load='1qqs' size='340' side='right' caption='[[1qqs]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1qqs]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QQS OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1QQS FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=DKA:DECANOIC+ACID'>DKA</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene></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=1qqs FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1qqs OCA], [http://pdbe.org/1qqs PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1qqs RCSB], [http://www.ebi.ac.uk/pdbsum/1qqs 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>  
== 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/qq/1qqs_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 ==
Neutrophil gelatinase associated lipocalin (NGAL), a constituent of neutrophil granules, is a member of the lipocalin family of binding proteins. NGAL can also be highly induced in epithelial cells in both inflammatory and neoplastic colorectal disease. NGAL is proposed to mediate inflammatory responses by sequestering neutrophil chemoattractants, particularly N-formylated tripeptides and possibly leukotriene B(4) and platelet activating factor. The crystal structures of NGAL display a typical lipocalin fold, albeit with an unusually large and atypically polar binding site, or calyx. The fold of NGAL is most similar to the epididymal retinoic acid-binding protein, another lipocalin, though the overall architecture of the calyces are very different. The crystal structures also reveal either sulfate ions or an adventitiously copurified fatty acid bound in the binding site. Neither ligand is displaced by added N-formylated tripeptides. The size, shape, and character of the NGAL calyx, as well as the low relative affinity for N-formylated tripeptides, suggest that neither the copurified fatty acid nor any of the proposed ligands are likely to be the preferred ligand of this protein. Comparisons between the crystal structures and the recently reported solution structure of NGAL reveal significant differences, in terms of both the details of the structure and the overall flexibility of the fold.

Ligand preference inferred from the structure of neutrophil gelatinase associated lipocalin.,Goetz DH, Willie ST, Armen RS, Bratt T, Borregaard N, Strong RK Biochemistry. 2000 Feb 29;39(8):1935-41. PMID:10684642<ref>PMID:10684642</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 1qqs" style="background-color:#fffaf0;"></div>

==See Also==
*[[Neutrophil gelatinase-associated lipocalin|Neutrophil gelatinase-associated lipocalin]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Human]]
[[Category: Armen, R]]
[[Category: Borregaard, N]]
[[Category: Bratt, T]]
[[Category: Goetz, D H]]
[[Category: Strong, R K]]
[[Category: Willie, S T]]
[[Category: Glycoprotein]]
[[Category: Neutrophil lipocalin]]
[[Category: Signal protein]]
[[Category: Sugar binding protein]]