View source for 4caj


==Crystallographic structure of the mouse SIGN-R1 CRD domain in complex with sialic acid==
<StructureSection load='4caj' size='340' side='right'caption='[[4caj]], [[Resolution|resolution]] 2.19&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4caj]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4CAJ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4CAJ 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]] 2.191&#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=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=SIA:O-SIALIC+ACID'>SIA</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=4caj FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4caj OCA], [https://pdbe.org/4caj PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4caj RCSB], [https://www.ebi.ac.uk/pdbsum/4caj PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4caj ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/C209B_MOUSE C209B_MOUSE] Probable pathogen-recognition receptor. May mediate the endocytosis of pathogens which are subsequently degraded in lysosomal compartments. May recognize in a calcium-dependent manner high mannose N-linked oligosaccharides in a variety of pathogen antigens. Is a receptor for ICAM3, probably by binding to mannose-like carbohydrates.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
SIGN-R1 is a principal receptor for microbial polysaccharides uptake and is responsible for C3 fixation via an unusual complement activation pathway on splenic marginal zone macrophages. In these macrophages, SIGN-R1 is also involved in anti-inflammatory activity of intravenous immunoglobulin by direct interaction with sialylated Fcs. The high-resolution crystal structures of SIGN-R1 carbohydrate recognition domain and its complexes with dextran sulfate or sialic acid, and of the sialylated Fc antibody provide insights into SIGN-R1's selective recognition of a-2,6-sialylated glycoproteins. Unexpectedly, an additional binding site has been found in the SIGNR1 carbohydrate recognition domain, structurally separate from the calcium-dependent carbohydrate-binding site. This secondary binding site could bind repetitive molecular patterns, as observed in microbial polysaccharides, in a calcium-independent manner. These two binding sites may allow SIGNR1 to simultaneously bind both immune glycoproteins and microbial polysaccharide components, accommodating SIGN-R1's ability to relate the recognition of microbes to the activation of the classical complement pathway.

Structural basis for selective recognition of endogenous and microbial polysaccharides by macrophage receptor SIGN-R1.,Silva-Martin N, Bartual SG, Ramirez-Aportela E, Chacon P, Park CG, Hermoso JA Structure. 2014 Nov 4;22(11):1595-606. PMID:25450767<ref>PMID:25450767</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4caj" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Mus musculus]]
[[Category: Bartual SG]]
[[Category: Hermoso JA]]
[[Category: Silva-Martin N]]