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| | ==High resolution structure of Siglec-7== | | ==High resolution structure of Siglec-7== |
| - | <StructureSection load='1o7s' size='340' side='right' caption='[[1o7s]], [[Resolution|resolution]] 1.75Å' scene=''> | + | <StructureSection load='1o7s' size='340' side='right'caption='[[1o7s]], [[Resolution|resolution]] 1.75Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[1o7s]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1O7S OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1O7S FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[1o7s]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1O7S OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1O7S FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CYS:CYSTEINE'>CYS</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=NDG:2-(ACETYLAMINO)-2-DEOXY-A-D-GLUCOPYRANOSE'>NDG</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.75Å</td></tr> |
| - | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1o7v|1o7v]]</td></tr>
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CYS:CYSTEINE'>CYS</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=NDG:2-(ACETYLAMINO)-2-DEOXY-A-D-GLUCOPYRANOSE'>NDG</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=1o7s FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1o7s OCA], [http://pdbe.org/1o7s PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1o7s RCSB], [http://www.ebi.ac.uk/pdbsum/1o7s PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1o7s ProSAT]</span></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=1o7s FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1o7s OCA], [https://pdbe.org/1o7s PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1o7s RCSB], [https://www.ebi.ac.uk/pdbsum/1o7s PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1o7s ProSAT]</span></td></tr> |
| | </table> | | </table> |
| | == Function == | | == Function == |
| - | [[http://www.uniprot.org/uniprot/SIGL7_HUMAN SIGL7_HUMAN]] Putative adhesion molecule that mediates sialic-acid dependent binding to cells. Preferentially binds to alpha-2,3- and alpha-2,6-linked sialic acid. Also binds disialogangliosides (disialogalactosyl globoside, disialyl lactotetraosylceramide and disialyl GalNAc lactotetraoslylceramide). The sialic acid recognition site may be masked by cis interactions with sialic acids on the same cell surface. In the immune response, may act as an inhibitory receptor upon ligand induced tyrosine phosphorylation by recruiting cytoplasmic phosphatase(s) via their SH2 domain(s) that block signal transduction through dephosphorylation of signaling molecules. Mediates inhibition of natural killer cells cytotoxicity. May play a role in hemopoiesis. Inhibits differentiation of CD34+ cell precursors towards myelomonocytic cell lineage and proliferation of leukemic myeloid cells (in vitro).<ref>PMID:10611343</ref> | + | [https://www.uniprot.org/uniprot/SIGL7_HUMAN SIGL7_HUMAN] Putative adhesion molecule that mediates sialic-acid dependent binding to cells. Preferentially binds to alpha-2,3- and alpha-2,6-linked sialic acid. Also binds disialogangliosides (disialogalactosyl globoside, disialyl lactotetraosylceramide and disialyl GalNAc lactotetraoslylceramide). The sialic acid recognition site may be masked by cis interactions with sialic acids on the same cell surface. In the immune response, may act as an inhibitory receptor upon ligand induced tyrosine phosphorylation by recruiting cytoplasmic phosphatase(s) via their SH2 domain(s) that block signal transduction through dephosphorylation of signaling molecules. Mediates inhibition of natural killer cells cytotoxicity. May play a role in hemopoiesis. Inhibits differentiation of CD34+ cell precursors towards myelomonocytic cell lineage and proliferation of leukemic myeloid cells (in vitro).<ref>PMID:10611343</ref> |
| | == Evolutionary Conservation == | | == Evolutionary Conservation == |
| | [[Image:Consurf_key_small.gif|200px|right]] | | [[Image:Consurf_key_small.gif|200px|right]] |
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| | <jmolCheckbox> | | <jmolCheckbox> |
| | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/o7/1o7s_consurf.spt"</scriptWhenChecked> | | <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/o7/1o7s_consurf.spt"</scriptWhenChecked> |
| - | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked> | + | <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.spt</scriptWhenUnchecked> |
| | <text>to colour the structure by Evolutionary Conservation</text> | | <text>to colour the structure by Evolutionary Conservation</text> |
| | </jmolCheckbox> | | </jmolCheckbox> |
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| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Human]] | + | [[Category: Homo sapiens]] |
| - | [[Category: Aalten, D M.F Van]] | + | [[Category: Large Structures]] |
| - | [[Category: Alphey, M S]] | + | [[Category: Alphey MS]] |
| - | [[Category: Attrill, H]] | + | [[Category: Attrill H]] |
| - | [[Category: Crocker, P R]] | + | [[Category: Crocker PR]] |
| - | [[Category: Cell adhesion]] | + | [[Category: Van Aalten DMF]] |
| - | [[Category: Immune system]]
| + | |
| - | [[Category: Immunoglobulin fold]]
| + | |
| - | [[Category: Lectin]]
| + | |
| - | [[Category: Sialic acid binding protein]]
| + | |
| - | [[Category: Siglec]]
| + | |
| Structural highlights
Function
SIGL7_HUMAN Putative adhesion molecule that mediates sialic-acid dependent binding to cells. Preferentially binds to alpha-2,3- and alpha-2,6-linked sialic acid. Also binds disialogangliosides (disialogalactosyl globoside, disialyl lactotetraosylceramide and disialyl GalNAc lactotetraoslylceramide). The sialic acid recognition site may be masked by cis interactions with sialic acids on the same cell surface. In the immune response, may act as an inhibitory receptor upon ligand induced tyrosine phosphorylation by recruiting cytoplasmic phosphatase(s) via their SH2 domain(s) that block signal transduction through dephosphorylation of signaling molecules. Mediates inhibition of natural killer cells cytotoxicity. May play a role in hemopoiesis. Inhibits differentiation of CD34+ cell precursors towards myelomonocytic cell lineage and proliferation of leukemic myeloid cells (in vitro).[1]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
Sialic acid-binding immunoglobulin-like lectins (Siglecs) recognize sialylated glycoconjugates and play a role in cell-cell recognition. Siglec-7 is expressed on natural killer cells and displays unique ligand binding properties different from other members of the Siglec family. Here we describe the high resolution structures of the N-terminal V-set Ig-like domain of Siglec-7 in two crystal forms, at 1.75 and 1.9 A. The latter crystal form reveals the full structure of this domain and allows us to speculate on the differential ligand binding properties displayed by members of the Siglec family. A fully ordered N-linked glycan is observed, tethered by tight interactions with symmetry-related protein molecules in the crystal. Comparison of the structure with that of sialoadhesin and a model of Siglec-9 shows that the unique preference of Siglec-7 for alpha(2,8)-linked disialic acid is likely to reside in the C-C' loop, which is variable in the Siglec family. In the Siglec-7 structure, the ligand-binding pocket is occupied by a loop of a symmetry-related molecule, mimicking the interactions with sialic acid.
High resolution crystal structures of Siglec-7. Insights into ligand specificity in the Siglec family.,Alphey MS, Attrill H, Crocker PR, van Aalten DM J Biol Chem. 2003 Jan 31;278(5):3372-7. Epub 2002 Nov 15. PMID:12438315[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Vitale C, Romagnani C, Falco M, Ponte M, Vitale M, Moretta A, Bacigalupo A, Moretta L, Mingari MC. Engagement of p75/AIRM1 or CD33 inhibits the proliferation of normal or leukemic myeloid cells. Proc Natl Acad Sci U S A. 1999 Dec 21;96(26):15091-6. PMID:10611343
- ↑ Alphey MS, Attrill H, Crocker PR, van Aalten DM. High resolution crystal structures of Siglec-7. Insights into ligand specificity in the Siglec family. J Biol Chem. 2003 Jan 31;278(5):3372-7. Epub 2002 Nov 15. PMID:12438315 doi:http://dx.doi.org/10.1074/jbc.M210602200
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