View source for 3alu


==Crystal structure of CEL-IV complexed with Raffinose==
<StructureSection load='3alu' size='340' side='right'caption='[[3alu]], [[Resolution|resolution]] 1.65&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3alu]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Cucumaria_echinata Cucumaria echinata]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3ALU OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3ALU 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]] 1.65&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=EDO:1,2-ETHANEDIOL'>EDO</scene>, <scene name='pdbligand=FRU:FRUCTOSE'>FRU</scene>, <scene name='pdbligand=GLA:ALPHA+D-GALACTOSE'>GLA</scene>, <scene name='pdbligand=GLC:ALPHA-D-GLUCOSE'>GLC</scene>, <scene name='pdbligand=PRD_900002:raffinose'>PRD_900002</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=3alu FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3alu OCA], [https://pdbe.org/3alu PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3alu RCSB], [https://www.ebi.ac.uk/pdbsum/3alu PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3alu ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q7M4F9_CUCEC Q7M4F9_CUCEC] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
CEL-IV is a C-type lectin isolated from a sea cucumber, Cucumaria echinata. This lectin is composed of four identical C-type carbohydrate-recognition domains (CRDs). X-ray crystallographic analysis of CEL-IV revealed that its tetrameric structure was stabilized by multiple interchain disulfide bonds among the subunits. Although CEL-IV has the EPN motif in its carbohydrate-binding sites, which is known to be characteristic of mannose-binding C-type CRDs, it showed preferential binding of galactose and N-acetylgalactosamine. Structural analyses of CEL-IV/melibiose and CEL-IV/raffinose complexes revealed that their galactose residues were recognized in an inverted orientation compared with mannose-binding C-type CRDs containing the EPN motif, by the aid of a stacking interaction with the side chain of Trp79. Changes in the environment of Trp79 induced by binding to galactose were detected by changes in the intrinsic fluorescence and UV-absorption spectra of WT CEL-IV and its site-directed mutants. The binding specificity of CEL-IV toward complex oligosaccharides was analyzed by frontal affinity chromatography using various pyridylamino-sugars, and the results indicated preferential binding to oligosaccharides containing Galbeta1-3/4(Fucalpha1-3/4)GlcNAc structures. These findings suggest that the specificity for oligosaccharides may be largely affected by interactions with amino acid residues in the binding site other than those determining the monosaccharide-specificity.

Galactose recognition by a tetrameric C-type lectin, CEL-IV, containing the EPN carbohydrate-recognition motif.,Hatakeyama T, Kamiya T, Kusunoki M, Nakamura-Tsuruta S, Hirabayashi J, Goda S, Unno H J Biol Chem. 2011 Jan 19. PMID:21247895<ref>PMID:21247895</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3alu" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Cucumaria echinata]]
[[Category: Large Structures]]
[[Category: Goda S]]
[[Category: Hatakeyama T]]
[[Category: Hozawa T]]
[[Category: Ishii K]]
[[Category: Kamiya T]]
[[Category: Kusunoki M]]
[[Category: Unno H]]