View source for 2zg3


==Crystal Structure of Two N-terminal Domains of Native Siglec-5 in Complex with 3'-Sialyllactose==
<StructureSection load='2zg3' size='340' side='right'caption='[[2zg3]], [[Resolution|resolution]] 3.00&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2zg3]] 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=2ZG3 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2ZG3 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]] 3&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BGC:BETA-D-GLUCOSE'>BGC</scene>, <scene name='pdbligand=GAL:BETA-D-GALACTOSE'>GAL</scene>, <scene name='pdbligand=SIA:O-SIALIC+ACID'>SIA</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=2zg3 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2zg3 OCA], [https://pdbe.org/2zg3 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2zg3 RCSB], [https://www.ebi.ac.uk/pdbsum/2zg3 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2zg3 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/SIGL5_HUMAN SIGL5_HUMAN] Putative adhesion molecule that mediates sialic-acid dependent binding to cells. Binds equally to alpha-2,3-linked and alpha-2,6-linked sialic acid. The sialic acid recognition site may be masked by cis interactions with sialic acids on the same cell surface.
== 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/zg/2zg3_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=2zg3 ConSurf].
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== Publication Abstract from PubMed ==
Sialic acid (Sia) Ig-like binding lectins are important mediators of recognition and signaling events among myeloid cells. To investigate the molecular mechanism underlying sialic acid Ig-like lectin (Siglec) functions, we determined the crystal structure of the two N-terminal extracellular domains of human myeloid cell inhibitory receptor Siglec-5 (CD170) and its complexes with two sialylated carbohydrates. The native structure revealed an unusual conformation of the CC' ligand specificity loop and a unique interdomain disulfide bond. The alpha(2,3)- and alpha(2,6)-sialyllactose complexed structures showed a conserved Sia recognition motif that involves both Arg124 and a portion of the G-strand in the V-set domain forming beta-sheet-like hydrogen bonds with the glycerol side chain of the Sia. Only few protein contacts to the subterminal sugars are observed and mediated by the highly variable GG' linker and CC' loop. These structural observations, in conjunction with surface plasmon resonance binding assays, provide mechanistic insights into linkage-dependent Siglec carbohydrate recognition and suggest that Siglec-5 and other CD33-related Siglec receptors are more promiscuous in sialoglycan recognition than previously understood.

Structural implications of Siglec-5-mediated sialoglycan recognition.,Zhuravleva MA, Trandem K, Sun PD J Mol Biol. 2008 Jan 11;375(2):437-47. Epub 2007 Oct 11. PMID:18022638<ref>PMID:18022638</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Sun PD]]
[[Category: Zhuravleva MA]]