View source for 4uso


==X-ray structure of the CCL2 lectin in complex with sialyl lewis X==
<StructureSection load='4uso' size='340' side='right'caption='[[4uso]], [[Resolution|resolution]] 1.95&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4uso]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Coprinopsis_cinerea Coprinopsis cinerea]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4USO OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4USO 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]] 1.95&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FUC:ALPHA-L-FUCOSE'>FUC</scene>, <scene name='pdbligand=GAL:BETA-D-GALACTOSE'>GAL</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=PRD_900121:Sialyl-Lewis+X+antigen,+beta+anomer'>PRD_900121</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=4uso FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4uso OCA], [https://pdbe.org/4uso PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4uso RCSB], [https://www.ebi.ac.uk/pdbsum/4uso PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4uso ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/B3GA02_COPCI B3GA02_COPCI] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Lectins are used as defense effector proteins against predators, parasites and pathogens by animal, plant and fungal innate defense systems. These proteins bind to specific glycoepitopes on the cell surfaces and thereby interfere with the proper cellular functions of the various antagonists. The exact cellular toxicity mechanism is in many cases unclear. Lectin CCL2 of the mushroom Coprinopsis cinerea was previously shown to be toxic for Caenorhabditis elegans and Drosophila melanogaster This toxicity is dependent on a single, high-affinity binding site for the trisaccharide GlcNAc(Fucalpha1,3)beta1,4GlcNAc, which is a hallmark of nematode and insect N-glycan cores. The carbohydrate-binding site is located at an unusual position on the protein surface when compared to other beta-trefoil lectins. Here, we show that CCL2 forms a compact dimer in solution and in crystals. Substitution of two amino acid residues at the dimer interface, R18A and F133A, interfered with dimerization of CCL2 and reduced toxicity but left carbohydrate-binding unaffected. These results, together with the positioning of the two carbohydrate-binding sites on the surface of the protein dimer, suggest that crosslinking of N-glycoproteins on the surface of intestinal cells of invertebrates is a crucial step in the mechanism of CCL2-mediated toxicity. Comparisons of the number and positioning of carbohydrate-binding sites among different dimerizing fungal beta-trefoil lectins revealed a considerable variability in the carbohydrate-binding patterns of these proteins, which are likely to correlate with their respective functions.

Dimerization of the fungal defense lectin CCL2 is essential for its toxicity against nematodes.,Bleuler-Martinez S, Stutz K, Sieber R, Collot M, Mallet JM, Hengartner M, Schubert M, Varrot A, Kunzler M Glycobiology. 2016 Nov 22. PMID:27980000<ref>PMID:27980000</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4uso" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Coprinopsis cinerea]]
[[Category: Large Structures]]
[[Category: Aebi M]]
[[Category: Bleuler-Martinez S]]
[[Category: Hengartner M]]
[[Category: Kunzler M]]
[[Category: Schubert M]]
[[Category: Sieber R]]
[[Category: Stutz M]]
[[Category: Varrot A]]