4wqq: Difference between revisions
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''' | ==Structure of EPNH mutant of CEL-I== | ||
<StructureSection load='4wqq' size='340' side='right' caption='[[4wqq]], [[Resolution|resolution]] 1.70Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[4wqq]] is a 4 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4WQQ OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=4WQQ FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</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=4wqq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4wqq OCA], [http://www.rcsb.org/pdb/explore.do?structureId=4wqq RCSB], [http://www.ebi.ac.uk/pdbsum/4wqq PDBsum]</span></td></tr> | |||
</table> | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
BACKGROUND: CEL-I is a galactose/N-acetylgalactosamine-specific C-type lectin isolated from the sea cucumber Cucumaria echinata. Its carbohydrate-binding site contains a QPD (Gln-Pro-Asp) motif, which is generally recognized as the galactose specificity-determining motif in the C-type lectins. In our previous study, replacement of the QPD motif by an EPN (Glu-Pro-Asn) motif led to a weak binding affinity for mannose. Therefore, we examined the effects of an additional mutation in the carbohydrate-binding site on the specificity of the lectin. METHODS: Trp105 of EPN-CEL-I was replaced by a histidine residue using site-directed mutagenesis, and the binding affinity of the resulting mutant, EPNH-CEL-I, was examined by sugar-polyamidoamine dendrimer assay, isothermal titration calorimetry, and glycoconjugate microarray analysis. Tertiary structure of the EPNH-CEL-I/mannose complex was determined by X-ray crystallographic analysis. RESULTS: Sugar-polyamidoamine dendrimer assay and glycoconjugate microarray analysis revealed a drastic change in the specificity of EPNH-CEL-I from galactose/N-acetylgalactosamine to mannose. The association constant of EPNH-CEL-I for mannose was determined to be 3.17x103M-1 at 25 degrees C. Mannose specificity of EPNH-CEL-I was achieved by stabilization of the binding of mannose in a correct orientation, in which the EPN motif can form proper hydrogen bonds with 3- and 4-hydroxy groups of the bound mannose. CONCLUSIONS: Specificity of CEL-I can be engineered by mutating a limited number of amino acid residues in addition to the QPD/EPN motifs. GENERAL SIGNIFICANCE: Versatility of the C-type carbohydrate-recognition domain structure in the recognition of various carbohydrate chains could become a promising platform to develop novel molecular recognition proteins. | |||
Mannose-recognition mutant of the galactose/N-acetylgalactosamine-specific C-type lectin CEL-I engineered by site-directed mutagenesis.,Moriuchi H, Unno H, Goda S, Tateno H, Hirabayashi J, Hatakeyama T Biochim Biophys Acta. 2015 Apr 11;1850(7):1457-1465. doi:, 10.1016/j.bbagen.2015.04.004. PMID:25869490<ref>PMID:25869490</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Hatakeyama, T]] | [[Category: Hatakeyama, T]] | ||
[[Category: Unno, H]] | [[Category: Unno, H]] | ||
[[Category: C-type lectin]] | |||
[[Category: Cel-i]] | |||
[[Category: Epnh munant]] | |||
[[Category: Mannose recognition]] | |||
[[Category: Sugar binding protein]] | |||
