View source for 2vdq


==INTEGRIN ALPHAIIBBETA3 HEADPIECE BOUND TO A CHIMERIC FIBRINOGEN GAMMA CHAIN PEPTIDE, HHLGGAKQRGDV==
<StructureSection load='2vdq' size='340' side='right' caption='[[2vdq]], [[Resolution|resolution]] 2.59&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2vdq]] is a 5 chain structure with sequence from [http://en.wikipedia.org/wiki/Human Human] and [http://en.wikipedia.org/wiki/Mus_musculus Mus musculus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2VDQ OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2VDQ 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=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NAG:N-ACETYL-D-GLUCOSAMINE'>NAG</scene>, <scene name='pdbligand=MAN:ALPHA-D-MANNOSE'>MAN</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1mk7|1mk7]], [[1m8o|1m8o]], [[1s4x|1s4x]], [[2vdn|2vdn]], [[1uv9|1uv9]], [[1tye|1tye]], [[1s4w|1s4w]], [[1mk9|1mk9]], [[1m1x|1m1x]], [[1rn0|1rn0]], [[1l5g|1l5g]], [[2vdm|2vdm]], [[1dpq|1dpq]], [[2vdo|2vdo]], [[2vdp|2vdp]], [[1jv2|1jv2]], [[1dpk|1dpk]], [[2vdr|2vdr]], [[2vdk|2vdk]], [[1kup|1kup]], [[1kuz|1kuz]], [[2vdl|2vdl]], [[1miz|1miz]], [[1u8c|1u8c]], [[1jx5|1jx5]], [[2vc2|2vc2]]</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=2vdq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2vdq OCA], [http://pdbe.org/2vdq PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2vdq RCSB], [http://www.ebi.ac.uk/pdbsum/2vdq PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2vdq ProSAT]</span></td></tr>
</table>
== Disease ==
[[http://www.uniprot.org/uniprot/ITA2B_HUMAN ITA2B_HUMAN]] Defects in ITGA2B are a cause of Glanzmann thrombasthenia (GT) [MIM:[http://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>  [[http://www.uniprot.org/uniprot/FIBG_HUMAN FIBG_HUMAN]] Defects in FGG are a cause of congenital afibrinogenemia (CAFBN) [MIM:[http://omim.org/entry/202400 202400]]. This rare autosomal recessive disorder is characterized by bleeding that varies from mild to severe and by complete absence or extremely low levels of plasma and platelet fibrinogen. Note=Patients with congenital fibrinogen abnormalities can manifest different clinical pictures. Some cases are clinically silent, some show a tendency toward bleeding and some show a predisposition for thrombosis with or without bleeding. [[http://www.uniprot.org/uniprot/ITB3_HUMAN ITB3_HUMAN]] Defects in ITGB3 are a cause of Glanzmann thrombasthenia (GT) [MIM:[http://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:2392682</ref> <ref>PMID:1371279</ref> <ref>PMID:1602006</ref> <ref>PMID:1438206</ref> <ref>PMID:8781422</ref> <ref>PMID:9376589</ref> <ref>PMID:9215749</ref> <ref>PMID:9790984</ref> <ref>PMID:9684783</ref> <ref>PMID:10233432</ref> <ref>PMID:11588040</ref> <ref>PMID:11897046</ref> <ref>PMID:12083483</ref> <ref>PMID:12353082</ref> <ref>PMID:15583747</ref> <ref>PMID:15634267</ref> <ref>PMID:15748237</ref>  
== Function ==
[[http://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. [[http://www.uniprot.org/uniprot/FIBG_HUMAN FIBG_HUMAN]] Fibrinogen has a double function: yielding monomers that polymerize into fibrin and acting as a cofactor in platelet aggregation. [[http://www.uniprot.org/uniprot/ITB3_HUMAN ITB3_HUMAN]] Integrin alpha-V/beta-3 is a receptor for cytotactin, fibronectin, laminin, matrix metalloproteinase-2, osteopontin, osteomodulin, prothrombin, thrombospondin, vitronectin and von Willebrand factor. Integrin alpha-IIb/beta-3 is a receptor for fibronectin, fibrinogen, plasminogen, prothrombin, thrombospondin and vitronectin. Integrins alpha-IIb/beta-3 and alpha-V/beta-3 recognize the sequence R-G-D in a wide array of ligands. Integrin alpha-IIb/beta-3 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 surface. In case of HIV-1 infection, the interaction with extracellular viral Tat protein seems to enhance angiogenesis in Kaposi's sarcoma lesions. 
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/vd/2vdq_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=2vdq ConSurf].
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== Publication Abstract from PubMed ==
Hemostasis and thrombosis (blood clotting) involve fibrinogen binding to integrin alpha(IIb)beta(3) on platelets, resulting in platelet aggregation. alpha(v)beta(3) binds fibrinogen via an Arg-Asp-Gly (RGD) motif in fibrinogen's alpha subunit. alpha(IIb)beta(3) also binds to fibrinogen; however, it does so via an unstructured RGD-lacking C-terminal region of the gamma subunit (gammaC peptide). These distinct modes of fibrinogen binding enable alpha(IIb)beta(3) and alpha(v)beta(3) to function cooperatively in hemostasis. In this study, crystal structures reveal the integrin alpha(IIb)beta(3)-gammaC peptide interface, and, for comparison, integrin alpha(IIb)beta(3) bound to a lamprey gammaC primordial RGD motif. Compared with RGD, the GAKQAGDV motif in gammaC adopts a different backbone configuration and binds over a more extended region. The integrin metal ion-dependent adhesion site (MIDAS) Mg(2+) ion binds the gammaC Asp side chain. The adjacent to MIDAS (ADMIDAS) Ca(2+) ion binds the gammaC C terminus, revealing a contribution for ADMIDAS in ligand binding. Structural data from this natively disordered gammaC peptide enhances our understanding of the involvement of gammaC peptide and integrin alpha(IIb)beta(3) in hemostasis and thrombosis.

Structural basis for distinctive recognition of fibrinogen gammaC peptide by the platelet integrin alphaIIbbeta3.,Springer TA, Zhu J, Xiao T J Cell Biol. 2008 Aug 25;182(4):791-800. Epub 2008 Aug 18. PMID:18710925<ref>PMID:18710925</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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<div class="pdbe-citations 2vdq" style="background-color:#fffaf0;"></div>

==See Also==
*[[Fibrinogen|Fibrinogen]]
*[[Integrin|Integrin]]
*[[3D structures of monoclonal antibody|3D structures of monoclonal antibody]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Human]]
[[Category: Mus musculus]]
[[Category: Springer, T A]]
[[Category: Xiao, T]]
[[Category: Zhu, J]]
[[Category: Antagonist]]
[[Category: Cell adhesion]]
[[Category: Cell adhesion-immune system complex]]
[[Category: Cleavage on pair of basic residue]]
[[Category: Disease mutation]]
[[Category: Fibrinogen binding]]
[[Category: Glycoprotein]]
[[Category: Host-virus interaction]]
[[Category: Integrin]]
[[Category: Membrane]]
[[Category: Phosphorylation]]
[[Category: Platelet integrin alphaiibbeta3]]
[[Category: Pyrrolidone carboxylic acid]]
[[Category: Receptor]]
[[Category: Transmembrane]]