View source for 1auq


==A1 DOMAIN OF VON WILLEBRAND FACTOR==
<StructureSection load='1auq' size='340' side='right'caption='[[1auq]], [[Resolution|resolution]] 2.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1auq]] 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=1AUQ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1AUQ 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]] 2.3&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CD:CADMIUM+ION'>CD</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=1auq FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1auq OCA], [https://pdbe.org/1auq PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1auq RCSB], [https://www.ebi.ac.uk/pdbsum/1auq PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1auq ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/VWF_HUMAN VWF_HUMAN] Defects in VWF are the cause of von Willebrand disease type 1 (VWD1) [MIM:[https://omim.org/entry/193400 193400]. A common hemorrhagic disorder due to defects in von Willebrand factor protein and resulting in impaired platelet aggregation. Von Willebrand disease type 1 is characterized by partial quantitative deficiency of circulating von Willebrand factor, that is otherwise structurally and functionally normal. Clinical manifestations are mucocutaneous bleeding, such as epistaxis and menorrhagia, and prolonged bleeding after surgery or trauma.<ref>PMID:10887119</ref> <ref>PMID:11698279</ref>   Defects in VWF are the cause of von Willebrand disease type 2 (VWD2) [MIM:[https://omim.org/entry/613554 613554]. A hemorrhagic disorder due to defects in von Willebrand factor protein and resulting in impaired platelet aggregation. Von Willebrand disease type 2 is characterized by qualitative deficiency and functional anomalies of von Willebrand factor. It is divided in different subtypes including 2A, 2B, 2M and 2N (Normandy variant). The mutant VWF protein in types 2A, 2B and 2M are defective in their platelet-dependent function, whereas the mutant protein in type 2N is defective in its ability to bind factor VIII. Clinical manifestations are mucocutaneous bleeding, such as epistaxis and menorrhagia, and prolonged bleeding after surgery or trauma.  Defects in VWF are the cause of von Willebrand disease type 3 (VWD3) [MIM:[https://omim.org/entry/277480 277480]. A severe hemorrhagic disorder due to a total or near total absence of von Willebrand factor in the plasma and cellular compartments, also leading to a profound deficiency of plasmatic factor VIII. Bleeding usually starts in infancy and can include epistaxis, recurrent mucocutaneous bleeding, excessive bleeding after minor trauma, and hemarthroses.
== Function ==
[https://www.uniprot.org/uniprot/VWF_HUMAN VWF_HUMAN] Important in the maintenance of hemostasis, it promotes adhesion of platelets to the sites of vascular injury by forming a molecular bridge between sub-endothelial collagen matrix and platelet-surface receptor complex GPIb-IX-V. Also acts as a chaperone for coagulation factor VIII, delivering it to the site of injury, stabilizing its heterodimeric structure and protecting it from premature clearance from plasma.
== 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/au/1auq_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview03.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=1auq ConSurf].
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== Publication Abstract from PubMed ==
von Willebrand Factor (vWF) is a multimeric protein that mediates platelet adhesion to exposed subendothelium at sites of vascular injury under conditions of high flow/shear. The A1 domain of vWF (vWF-A1) forms the principal binding site for platelet glycoprotein Ib (GpIb), an interaction that is tightly regulated. We report here the crystal structure of the vWF-A1 domain at 2.3-A resolution. As expected, the overall fold is similar to that of the vWF-A3 and integrin I domains. However, the structure also contains N- and C-terminal arms that wrap across the lower surface of the domain. Unlike the integrin I domains, vWF-A1 does not contain a metal ion-dependent adhesion site motif. Analysis of the available mutagenesis data suggests that the activator botrocetin binds to the right-hand face of the domain containing helices alpha5 and alpha6. Possible binding sites for GpIb are the front and upper surfaces of the domain. Natural mutations that lead to constitutive GpIb binding (von Willebrand type IIb disease) cluster in a different site, at the interface between the lower surface and the terminal arms, suggesting that they disrupt a regulatory region rather than forming part of the primary GpIb binding site. A possible pathway for propagating structural changes from the regulatory region to the ligand-binding surface is discussed.

Crystal structure of the von Willebrand Factor A1 domain and implications for the binding of platelet glycoprotein Ib.,Emsley J, Cruz M, Handin R, Liddington R J Biol Chem. 1998 Apr 24;273(17):10396-401. PMID:9553097<ref>PMID:9553097</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Von Willebrand Factor|Von Willebrand Factor]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Cruz M]]
[[Category: Emsley J]]
[[Category: Handin R]]
[[Category: Liddington R]]