3by0

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Revision as of 17:23, 5 August 2016

Crystal structure of Siderocalin (NGAL, Lipocalin 2) W79A-R81A complexed with Ferric Enterobactin

Structural highlights

3by0 is a 3 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	, , , ,
Gene:	lcn2, ngal, hnl (Homo sapiens)
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[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.^[1]

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 PubMed

The siderophore enterobactin (Ent) is produced by enteric bacteria to mediate iron uptake. Ent scavenges iron and is taken up by the bacteria as the highly stable ferric complex [Fe (III)(Ent)] (3-). This complex is also a specific target of the mammalian innate immune system protein, Siderocalin (Scn), which acts as an antibacterial agent by specifically sequestering siderophores and their ferric complexes during infection. Recent literature suggesting that Scn may also be involved in cellular iron transport has increased the importance of understanding the mechanism of siderophore interception and clearance by Scn; Scn is observed to release iron in acidic endosomes and [Fe (III)(Ent)] (3-) is known to undergo a change from catecholate to salicylate coordination in acidic conditions, which is predicted to be sterically incompatible with the Scn binding pocket (also referred to as the calyx). To investigate the interactions between the ferric Ent complex and Scn at different pH values, two recombinant forms of Scn with mutations in three residues lining the calyx were prepared: Scn-W79A/R81A and Scn-Y106F. Binding studies and crystal structures of the Scn-W79A/R81A:[Fe (III)(Ent)] (3-) and Scn-Y106F:[Fe (III)(Ent)] (3-) complexes confirm that such mutations do not affect the overall conformation of the protein but do weaken significantly its affinity for [Fe (III)(Ent)] (3-). Fluorescence, UV-vis, and EXAFS spectroscopies were used to determine Scn/siderophore dissociation constants and to characterize the coordination mode of iron over a wide pH range, in the presence of both mutant proteins and synthetic salicylate analogues of Ent. While Scn binding hinders salicylate coordination transformation, strong acidification results in the release of iron and degraded siderophore. Iron release may therefore result from a combination of Ent degradation and coordination change.

The siderocalin/enterobactin interaction: a link between mammalian immunity and bacterial iron transport.,Abergel RJ, Clifton MC, Pizarro JC, Warner JA, Shuh DK, Strong RK, Raymond KN J Am Chem Soc. 2008 Aug 27;130(34):11524-34. Epub 2008 Aug 5. PMID:18680288^[2]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Yang J, Goetz D, Li JY, Wang W, Mori K, Setlik D, Du T, Erdjument-Bromage H, Tempst P, Strong R, Barasch J. An iron delivery pathway mediated by a lipocalin. Mol Cell. 2002 Nov;10(5):1045-56. PMID:12453413
↑ Abergel RJ, Clifton MC, Pizarro JC, Warner JA, Shuh DK, Strong RK, Raymond KN. The siderocalin/enterobactin interaction: a link between mammalian immunity and bacterial iron transport. J Am Chem Soc. 2008 Aug 27;130(34):11524-34. Epub 2008 Aug 5. PMID:18680288 doi:10.1021/ja803524w

1 Structural highlights
2 Function
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 See Also
6 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/3by0"

@@ Line 1: / Line 1: @@
 ==Crystal structure of Siderocalin (NGAL, Lipocalin 2) W79A-R81A complexed with Ferric Enterobactin==
 <StructureSection load='3by0' size='340' side='right' caption='[[3by0]], [[Resolution|resolution]] 2.57&Aring;' scene=''>
@@ Line 5: / Line 6: @@
 </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=DBH:2,3-DIHYDROXY-BENZOIC+ACID'>DBH</scene>, <scene name='pdbligand=DBS:2-(2,3-DIHYDROXY-BENZOYLAMINO)-3-HYDROXY-PROPIONIC+ACID'>DBS</scene>, <scene name='pdbligand=FE:FE+(III)+ION'>FE</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
 <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">lcn2, ngal, hnl ([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=3by0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3by0 OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3by0 RCSB], [http://www.ebi.ac.uk/pdbsum/3by0 PDBsum]</span></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=3by0 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3by0 OCA], [http://pdbe.org/3by0 PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=3by0 RCSB], [http://www.ebi.ac.uk/pdbsum/3by0 PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=3by0 ProSAT]</span></td></tr>
 </table>
 == Function ==
@@ Line 17: / Line 18: @@
     <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].
+</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=3by0 ConSurf].
 <div style="clear:both"></div>
 <div style="background-color:#fffaf0;">
@@ Line 27: / Line 28: @@
 From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
 </div>
+<div class="pdbe-citations 3by0" style="background-color:#fffaf0;"></div>
 ==See Also==

3by0

From Proteopedia

Revision as of 17:23, 5 August 2016

Crystal structure of Siderocalin (NGAL, Lipocalin 2) W79A-R81A complexed with Ferric Enterobactin

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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