1dx5: Difference between revisions
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==Overview== | ==Overview== | ||
The serine proteinase alpha-thrombin causes blood clotting through | The serine proteinase alpha-thrombin causes blood clotting through proteolytic cleavage of fibrinogen and protease-activated receptors and amplifies its own generation by activating the essential clotting factors V and VIII. Thrombomodulin, a transmembrane thrombin receptor with six contiguous epidermal growth factor-like domains (TME1-6), profoundly alters the substrate specificity of thrombin from pro- to anticoagulant by activating protein C. Activated protein C then deactivates the coagulation cascade by degrading activated factors V and VIII. The thrombin-thrombomodulin complex inhibits fibrinolysis by activating the procarboxypeptidase thrombin-activatable fibrinolysis inhibitor. Here we present the 2.3 A crystal structure of human alpha-thrombin bound to the smallest thrombomodulin fragment required for full protein-C co-factor activity, TME456. The Y-shaped thrombomodulin fragment binds to thrombin's anion-binding exosite-I, preventing binding of procoagulant substrates. Thrombomodulin binding does not seem to induce marked allosteric structural rearrangements at the thrombin active site. Rather, docking of a protein C model to thrombin-TME456 indicates that TME45 may bind substrates in such a manner that their zymogen-activation cleavage sites are presented optimally to the unaltered thrombin active site. | ||
==Disease== | ==Disease== | ||
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[[Category: Huber, R.]] | [[Category: Huber, R.]] | ||
[[Category: Iwanaga, Y.]] | [[Category: Iwanaga, Y.]] | ||
[[Category: Light, D | [[Category: Light, D R.]] | ||
[[Category: Morser, J.]] | [[Category: Morser, J.]] | ||
[[Category: Pagila, R.]] | [[Category: Pagila, R.]] | ||
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[[Category: serine proteinase]] | [[Category: serine proteinase]] | ||
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 12:21:25 2008'' | ||
Revision as of 13:21, 21 February 2008
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CRYSTAL STRUCTURE OF THE THROMBIN-THROMBOMODULIN COMPLEX
OverviewOverview
The serine proteinase alpha-thrombin causes blood clotting through proteolytic cleavage of fibrinogen and protease-activated receptors and amplifies its own generation by activating the essential clotting factors V and VIII. Thrombomodulin, a transmembrane thrombin receptor with six contiguous epidermal growth factor-like domains (TME1-6), profoundly alters the substrate specificity of thrombin from pro- to anticoagulant by activating protein C. Activated protein C then deactivates the coagulation cascade by degrading activated factors V and VIII. The thrombin-thrombomodulin complex inhibits fibrinolysis by activating the procarboxypeptidase thrombin-activatable fibrinolysis inhibitor. Here we present the 2.3 A crystal structure of human alpha-thrombin bound to the smallest thrombomodulin fragment required for full protein-C co-factor activity, TME456. The Y-shaped thrombomodulin fragment binds to thrombin's anion-binding exosite-I, preventing binding of procoagulant substrates. Thrombomodulin binding does not seem to induce marked allosteric structural rearrangements at the thrombin active site. Rather, docking of a protein C model to thrombin-TME456 indicates that TME45 may bind substrates in such a manner that their zymogen-activation cleavage sites are presented optimally to the unaltered thrombin active site.
DiseaseDisease
Known diseases associated with this structure: Dysprothrombinemia OMIM:[176930], Hyperprothrombinemia OMIM:[176930], Hypoprothrombinemia OMIM:[176930], Myocardial infarction, susceptibility to OMIM:[188040], Thrombophilia due to thrombomodulin defect OMIM:[188040]
About this StructureAbout this Structure
1DX5 is a Protein complex structure of sequences from Homo sapiens with , , and as ligands. Active as Thrombin, with EC number 3.4.21.5 Known structural/functional Sites: , , and . Full crystallographic information is available from OCA.
ReferenceReference
Structural basis for the anticoagulant activity of the thrombin-thrombomodulin complex., Fuentes-Prior P, Iwanaga Y, Huber R, Pagila R, Rumennik G, Seto M, Morser J, Light DR, Bode W, Nature. 2000 Mar 30;404(6777):518-25. PMID:10761923
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