View source for 3zdx


==Integrin alphaIIB beta3 headpiece and RGD peptide complex==
<StructureSection load='3zdx' size='340' side='right'caption='[[3zdx]], [[Resolution|resolution]] 2.45&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3zdx]] is a 8 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] and [https://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3ZDX OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3ZDX 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]] 2.45&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=BMA:BETA-D-MANNOSE'>BMA</scene>, <scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene>, <scene name='pdbligand=MN:MANGANESE+(II)+ION'>MN</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</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=3zdx FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3zdx OCA], [https://pdbe.org/3zdx PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3zdx RCSB], [https://www.ebi.ac.uk/pdbsum/3zdx PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3zdx ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/ITA2B_HUMAN ITA2B_HUMAN] Defects in ITGA2B are a cause of Glanzmann thrombasthenia (GT) [MIM:[https://omim.org/entry/273800 273800]; also known as thrombasthenia of Glanzmann and Naegeli. GT is the most common inherited disease of platelets. It is an autosomal recessive disorder characterized by mucocutaneous bleeding of mild-to-moderate severity and the inability of this integrin to recognize macromolecular or synthetic peptide ligands. GT has been classified clinically into types I and II. In type I, platelets show absence of the glycoprotein IIb/beta-3 complexes at their surface and lack fibrinogen and clot retraction capability. In type II, the platelets express the glycoprotein IIb/beta-3 complex at reduced levels (5-20% controls), have detectable amounts of fibrinogen, and have low or moderate clot retraction capability. The platelets of GT 'variants' have normal or near normal (60-100%) expression of dysfunctional receptors.<ref>PMID:8282784</ref> <ref>PMID:7508443</ref> <ref>PMID:7706461</ref> <ref>PMID:8704171</ref> <ref>PMID:9215749</ref> <ref>PMID:9473221</ref> <ref>PMID:9763559</ref> <ref>PMID:9722314</ref> <ref>PMID:9734640</ref> <ref>PMID:9920835</ref> <ref>PMID:10607701</ref> <ref>PMID:11798398</ref> <ref>PMID:12181054</ref> <ref>PMID:12083483</ref> <ref>PMID:12424194</ref> <ref>PMID:12506038</ref> <ref>PMID:15099289</ref> <ref>PMID:15219201</ref> <ref>PMID:17018384</ref> 
== Function ==
[https://www.uniprot.org/uniprot/ITA2B_HUMAN ITA2B_HUMAN] Integrin alpha-IIb/beta-3 is a receptor for fibronectin, fibrinogen, plasminogen, prothrombin, thrombospondin and vitronectin. It recognizes the sequence R-G-D in a wide array of ligands. It recognizes the sequence H-H-L-G-G-G-A-K-Q-A-G-D-V in fibrinogen gamma chain. Following activation integrin alpha-IIb/beta-3 brings about platelet/platelet interaction through binding of soluble fibrinogen. This step leads to rapid platelet aggregation which physically plugs ruptured endothelial cell surface.
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Carefully soaking crystals with Arg-Gly-Asp (RGD) peptides, we captured eight distinct RGD-bound conformations of the alphaIIbbeta3 integrin headpiece. Starting from the closed betaI domain conformation, we saw six intermediate betaI conformations and finally the fully open betaI with the hybrid domain swung out in the crystal lattice. The beta1-alpha1 backbone that hydrogen bonds to the Asp side chain of RGD was the first element to move followed by adjacent to metal ion-dependent adhesion site Ca(2+), alpha1 helix, alpha1' helix, beta6-alpha7 loop, alpha7 helix, and hybrid domain. We define in atomic detail how conformational change was transmitted over long distances in integrins, 40 A from the ligand binding site to the opposite end of the betaI domain and 80 A to the far end of the hybrid domain. During these movements, RGD slid in its binding groove toward alphaIIb, and its Arg side chain became ordered. RGD concentration requirements in soaking suggested a &gt;200-fold higher affinity after opening. The thermodynamic cycle shows how higher affinity pays the energetic cost of opening.

Complete integrin headpiece opening in eight steps.,Zhu J, Zhu J, Springer TA J Cell Biol. 2013 Jun 24;201(7):1053-68. doi: 10.1083/jcb.201212037. PMID:23798730<ref>PMID:23798730</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 3zdx" style="background-color:#fffaf0;"></div>

==See Also==
*[[Integrin 3D structures|Integrin 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Mus musculus]]
[[Category: Springer TA]]
[[Category: Zhu JH]]
[[Category: Zhu JQ]]