6a1v: Difference between revisions

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'''Unreleased structure'''


The entry 6a1v is ON HOLD until Paper Publication
==Charcot-Leyden crystal protein/Galectin-10 variant E33Q==
<StructureSection load='6a1v' size='340' side='right' caption='[[6a1v]], [[Resolution|resolution]] 1.98&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[6a1v]] is a 1 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6A1V OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6A1V FirstGlance]. <br>
</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=6a1v FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6a1v OCA], [http://pdbe.org/6a1v PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6a1v RCSB], [http://www.ebi.ac.uk/pdbsum/6a1v PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6a1v ProSAT]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/LEG10_HUMAN LEG10_HUMAN]] Regulates immune responses through the recognition of cell-surface glycans. Essential for the anergy and suppressive function of CD25-positive regulatory T-cells (Treg).<ref>PMID:17502455</ref>  
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Charcot-Leyden crystal protein/Gal-10, abundantly expressed in eosinophils and basophils, is related to several immune diseases. Recently, crystallographic and biochemical studies showed that Gal-10 cannot bind lactose, because a glutamate residue (Glu33) from another monomer blocks the binding site. Moreover, Gal-10 actually forms a novel dimeric structure compared to other galectins. To investigate the role that Glu33 plays in inhibiting lactose binding, we mutated this residue to glutamine, aspartate, and alanine. The structure of E33A shows that Gal-10 can now bind lactose. In the hemagglutination assay, lactose could inhibit E33A from inducing chicken erythrocyte agglutination. Furthermore, we identified a tryptophan residue (Trp127) at the interface of homodimer that is crucial for Gal-10 dimerization. The variant W127A, which exists as a monomer, exhibited higher hemagglutination activity than wild type Gal-10. The solid phase assay also showed that W127A could bind to lactose-modified sepharose-6B, whereas wild type Gal-10 could not. This indicates that the open carbohydrate-binding site of the W127A monomer can bind to lactose. In addition, the distribution of EGFP-tagged Gal-10 and its variants in HeLa cells was investigated. Because Trp72 is the highly conserved in the ligand binding sites of galectins, we used EGFP-tagged W72A to show that Gal-10 could not be transported into the nucleus, indicating that Trp72 is crucial for Gal-10 transport into that organelle.


Authors: Su, J.Y.
Identification of key amino acid residues determining ligand binding specificity, homodimerization and cellular distribution of human galectin-10.,Su J, Song C, Si Y, Cui L, Yang T, Li Y, Wang H, Tai G, Zhou Y Glycobiology. 2019 Jan 1;29(1):85-93. doi: 10.1093/glycob/cwy087. PMID:30239701<ref>PMID:30239701</ref>


Description: Charcot-Leyden crystal protein/Galectin-10 variant E33Q
From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
[[Category: Unreleased Structures]]
</div>
[[Category: Su, J.Y]]
<div class="pdbe-citations 6a1v" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Su, J]]
[[Category: Charcot-leyden crystal protein/galectin-10 variant e33q]]
[[Category: Protein binding]]

Revision as of 11:13, 26 December 2018

Charcot-Leyden crystal protein/Galectin-10 variant E33QCharcot-Leyden crystal protein/Galectin-10 variant E33Q

Structural highlights

6a1v is a 1 chain structure. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[LEG10_HUMAN] Regulates immune responses through the recognition of cell-surface glycans. Essential for the anergy and suppressive function of CD25-positive regulatory T-cells (Treg).[1]

Publication Abstract from PubMed

Charcot-Leyden crystal protein/Gal-10, abundantly expressed in eosinophils and basophils, is related to several immune diseases. Recently, crystallographic and biochemical studies showed that Gal-10 cannot bind lactose, because a glutamate residue (Glu33) from another monomer blocks the binding site. Moreover, Gal-10 actually forms a novel dimeric structure compared to other galectins. To investigate the role that Glu33 plays in inhibiting lactose binding, we mutated this residue to glutamine, aspartate, and alanine. The structure of E33A shows that Gal-10 can now bind lactose. In the hemagglutination assay, lactose could inhibit E33A from inducing chicken erythrocyte agglutination. Furthermore, we identified a tryptophan residue (Trp127) at the interface of homodimer that is crucial for Gal-10 dimerization. The variant W127A, which exists as a monomer, exhibited higher hemagglutination activity than wild type Gal-10. The solid phase assay also showed that W127A could bind to lactose-modified sepharose-6B, whereas wild type Gal-10 could not. This indicates that the open carbohydrate-binding site of the W127A monomer can bind to lactose. In addition, the distribution of EGFP-tagged Gal-10 and its variants in HeLa cells was investigated. Because Trp72 is the highly conserved in the ligand binding sites of galectins, we used EGFP-tagged W72A to show that Gal-10 could not be transported into the nucleus, indicating that Trp72 is crucial for Gal-10 transport into that organelle.

Identification of key amino acid residues determining ligand binding specificity, homodimerization and cellular distribution of human galectin-10.,Su J, Song C, Si Y, Cui L, Yang T, Li Y, Wang H, Tai G, Zhou Y Glycobiology. 2019 Jan 1;29(1):85-93. doi: 10.1093/glycob/cwy087. PMID:30239701[2]

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

References

  1. Kubach J, Lutter P, Bopp T, Stoll S, Becker C, Huter E, Richter C, Weingarten P, Warger T, Knop J, Mullner S, Wijdenes J, Schild H, Schmitt E, Jonuleit H. Human CD4+CD25+ regulatory T cells: proteome analysis identifies galectin-10 as a novel marker essential for their anergy and suppressive function. Blood. 2007 Sep 1;110(5):1550-8. doi: 10.1182/blood-2007-01-069229. Epub 2007 May, 14. PMID:17502455 doi:http://dx.doi.org/10.1182/blood-2007-01-069229
  2. Su J, Song C, Si Y, Cui L, Yang T, Li Y, Wang H, Tai G, Zhou Y. Identification of key amino acid residues determining ligand binding specificity, homodimerization and cellular distribution of human galectin-10. Glycobiology. 2019 Jan 1;29(1):85-93. doi: 10.1093/glycob/cwy087. PMID:30239701 doi:http://dx.doi.org/10.1093/glycob/cwy087

6a1v, resolution 1.98Å

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