View source for 2wpk


==factor IXa superactive triple mutant, ethylene glycol-soaked==
<StructureSection load='2wpk' size='340' side='right' caption='[[2wpk]], [[Resolution|resolution]] 2.21&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2wpk]] is a 3 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2WPK OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=2WPK 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=EDO:1,2-ETHANEDIOL'>EDO</scene></td></tr>
<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=DPN:D-PHENYLALANINE'>DPN</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1edm|1edm]], [[1cfh|1cfh]], [[2wpm|2wpm]], [[1mgx|1mgx]], [[1cfi|1cfi]], [[2wpi|2wpi]], [[2wpl|2wpl]], [[2wph|2wph]], [[2wpj|2wpj]], [[1ixa|1ixa]], [[1rfn|1rfn]], [[1nl0|1nl0]]</td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/Coagulation_factor_IXa Coagulation factor IXa], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=3.4.21.22 3.4.21.22] </span></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=2wpk FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2wpk OCA], [http://pdbe.org/2wpk PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=2wpk RCSB], [http://www.ebi.ac.uk/pdbsum/2wpk PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=2wpk ProSAT]</span></td></tr>
</table>
== Disease ==
[[http://www.uniprot.org/uniprot/FA9_HUMAN FA9_HUMAN]] Defects in F9 are the cause of recessive X-linked hemophilia B (HEMB) [MIM:[http://omim.org/entry/306900 306900]]; also known as Christmas disease.<ref>PMID:8295821</ref> <ref>PMID:2592373</ref> <ref>PMID:2743975</ref> <ref>PMID:6603618</ref> <ref>PMID:3009023</ref> <ref>PMID:3790720</ref> <ref>PMID:3401602</ref> <ref>PMID:3243764</ref> <ref>PMID:2713493</ref> <ref>PMID:2714791</ref> <ref>PMID:2773937</ref> <ref>PMID:2775660</ref> <ref>PMID:2753873</ref> <ref>PMID:2738071</ref> <ref>PMID:2472424</ref> <ref>PMID:2339358</ref> <ref>PMID:2372509</ref> <ref>PMID:2162822</ref> <ref>PMID:1958666</ref> <ref>PMID:1902289</ref> <ref>PMID:1346975</ref> <ref>PMID:1615485</ref> <ref>PMID:8257988</ref> <ref>PMID:8076946</ref> <ref>PMID:8199596</ref> <ref>PMID:7981722</ref> <ref>PMID:8680410</ref> <ref>PMID:9222764</ref> <ref>PMID:9590153</ref> <ref>PMID:9452115</ref> <ref>PMID:9600455</ref> <ref>PMID:10698280</ref> <ref>PMID:10094553</ref> <ref>PMID:11122099</ref> <ref>PMID:12588353</ref> <ref>PMID:12604421</ref>   Note=Mutations in position 43 (Oxford-3, San Dimas) and 46 (Cambridge) prevents cleavage of the propeptide, mutation in position 93 (Alabama) probably fails to bind to cell membranes, mutation in position 191 (Chapel-Hill) or in position 226 (Nagoya OR Hilo) prevent cleavage of the activation peptide.  Defects in F9 are the cause of thrombophilia due to factor IX defect (THPH8) [MIM:[http://omim.org/entry/300807 300807]]. A hemostatic disorder characterized by a tendency to thrombosis.<ref>PMID:19846852</ref>  
== Function ==
[[http://www.uniprot.org/uniprot/FA9_HUMAN FA9_HUMAN]] Factor IX is a vitamin K-dependent plasma protein that participates in the intrinsic pathway of blood coagulation by converting factor X to its active form in the presence of Ca(2+) ions, phospholipids, and factor VIIIa. 
== 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/wp/2wpk_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=2wpk ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Human coagulation factor IX serves both to maintain and to control blood coagulation. The dual function of this hemophilic factor is implemented by a tiered activation mechanism. Processed two-chain factor IXa is catalytically silent; only together with its cofactor VIIIa does factor IXa form the highly potent Xase complex. The detailed mechanism of this secondary activation has remained elusive so far. Here we present the crystal structures of Xase-like factor IXa mutants with several-thousand-fold activity enhancement that mimic the secondary activation by Xase formation. The structures reveal how cofactor-triggered and substrate-assisted modulations in the factor IXa 99- and 60-loops cooperate in S4 through S2' formation, allowing for productive substrate recognition. We could further physically map and visualize a distinct communication line, along which agonists such as Ca(2+) direct their effects to the active site and vice versa.

Structural basis of the cofactor- and substrate-assisted activation of human coagulation factor IXa.,Zogg T, Brandstetter H Structure. 2009 Dec 9;17(12):1669-78. PMID:20004170<ref>PMID:20004170</ref>

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

==See Also==
*[[Factor IX|Factor IX]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Coagulation factor IXa]]
[[Category: Brandstetter, H]]
[[Category: Zogg, T]]
[[Category: Blood clotting]]
[[Category: Hemophilia]]
[[Category: Hemostasis]]
[[Category: Hydrolase]]