View source for 4hfp


==Structure of thrombin mutant S195a bound to the active site inhibitor argatroban==
<StructureSection load='4hfp' size='340' side='right'caption='[[4hfp]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4hfp]] is a 4 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=4HFP OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4HFP 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]] 2.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=15U:(2R,4R)-4-METHYL-1-(N~2~-{[(3S)-3-METHYL-1,2,3,4-TETRAHYDROQUINOLIN-8-YL]SULFONYL}-L-ARGINYL)PIPERIDINE-2-CARBOXYLIC+ACID'>15U</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</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=4hfp FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4hfp OCA], [https://pdbe.org/4hfp PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4hfp RCSB], [https://www.ebi.ac.uk/pdbsum/4hfp PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4hfp ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/THRB_HUMAN THRB_HUMAN] Defects in F2 are the cause of factor II deficiency (FA2D) [MIM:[https://omim.org/entry/613679 613679]. It is a very rare blood coagulation disorder characterized by mucocutaneous bleeding symptoms. The severity of the bleeding manifestations correlates with blood factor II levels.<ref>PMID:14962227</ref> <ref>PMID:6405779</ref> <ref>PMID:3771562</ref> <ref>PMID:3567158</ref> <ref>PMID:3801671</ref> <ref>PMID:3242619</ref> <ref>PMID:2719946</ref> <ref>PMID:1354985</ref> <ref>PMID:1421398</ref> <ref>PMID:1349838</ref> <ref>PMID:7865694</ref> <ref>PMID:7792730</ref>   Genetic variations in F2 may be a cause of susceptibility to ischemic stroke (ISCHSTR) [MIM:[https://omim.org/entry/601367 601367]; also known as cerebrovascular accident or cerebral infarction. A stroke is an acute neurologic event leading to death of neural tissue of the brain and resulting in loss of motor, sensory and/or cognitive function. Ischemic strokes, resulting from vascular occlusion, is considered to be a highly complex disease consisting of a group of heterogeneous disorders with multiple genetic and environmental risk factors.<ref>PMID:15534175</ref>   Defects in F2 are the cause of thrombophilia due to thrombin defect (THPH1) [MIM:[https://omim.org/entry/188050 188050]. It is a multifactorial disorder of hemostasis characterized by abnormal platelet aggregation in response to various agents and recurrent thrombi formation. Note=A common genetic variation in the 3-prime untranslated region of the prothrombin gene is associated with elevated plasma prothrombin levels and an increased risk of venous thrombosis.  Defects in F2 are associated with susceptibility to pregnancy loss, recurrent, type 2 (RPRGL2) [MIM:[https://omim.org/entry/614390 614390]. A common complication of pregnancy, resulting in spontaneous abortion before the fetus has reached viability. The term includes all miscarriages from the time of conception until 24 weeks of gestation. Recurrent pregnancy loss is defined as 3 or more consecutive spontaneous abortions.<ref>PMID:11506076</ref> 
== Function ==
[https://www.uniprot.org/uniprot/THRB_HUMAN THRB_HUMAN] Thrombin, which cleaves bonds after Arg and Lys, converts fibrinogen to fibrin and activates factors V, VII, VIII, XIII, and, in complex with thrombomodulin, protein C. Functions in blood homeostasis, inflammation and wound healing.<ref>PMID:2856554</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Trypsin-like proteases are synthesized as inactive zymogens and convert to the mature form upon activation by specific enzymes, often assisted by cofactors. Central to this paradigm is that the zymogen does not convert spontaneously to the mature enzyme, which in turn does not feed back to activate its zymogen form. In the blood, the zymogens prothrombin and prethrombin-2 require the prothrombinase complex to be converted to the mature protease thrombin, which is unable to activate prothrombin or prethrombin-2. Here, we show that replacement of key residues within the activation domain causes these zymogens to spontaneously convert to thrombin. The conversion is started by the zymogen itself, which is capable of binding ligands at the active site, and is abrogated by inactivation of the catalytic residue Ser-195. The product of autoactivation is functionally and structurally equivalent to wild-type thrombin. Zymogen autoactivation is explained by conformational selection, a basic property of the trypsin fold uncovered by structural and rapid kinetics studies. Both the zymogen and protease undergo a pre-existing equilibrium between active and inactive forms. The equilibrium regulates catalytic activity in the protease and has the potential to unleash activity in the zymogen to produce autoactivation. A new strategy emerges for the facile production of enzymes through zymogen autoactivation that is broadly applicable to trypsin-like proteases of biotechnological and clinical interest.

Autoactivation of thrombin precursors.,Pozzi N, Chen Z, Zapata F, Niu W, Barranco-Medina S, Pelc LA, Di Cera E J Biol Chem. 2013 Apr 19;288(16):11601-10. doi: 10.1074/jbc.M113.451542. Epub, 2013 Mar 6. PMID:23467412<ref>PMID:23467412</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4hfp" style="background-color:#fffaf0;"></div>

==See Also==
*[[Thrombin 3D Structures|Thrombin 3D Structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Barranco-Medina S]]
[[Category: Chen Z]]
[[Category: Di Cera E]]
[[Category: Lin W]]
[[Category: Pelc LA]]
[[Category: Pozzi N]]
[[Category: Zapata F]]