1dx5
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| , resolution 2.30Å | |||||||
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| Sites: | , , and | ||||||
| Ligands: | , , , , | ||||||
| Activity: | Thrombin, with EC number 3.4.21.5 | ||||||
| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
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.
About this StructureAbout this Structure
1DX5 is a Protein complex structure of sequences from Homo sapiens. 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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