2aip
Crystal structure of native protein C activator from the venom of copperhead snake Agkistrodon contortrix contortrixCrystal structure of native protein C activator from the venom of copperhead snake Agkistrodon contortrix contortrix
Structural highlights
FunctionVSPCA_AGKCO Snake venom serine protease that selectively cleaves the heavy chain of protein C (PROC). This activation is thrombomodulin-independent.[1] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedProtein C activation initiated by the thrombin-thrombomodulin complex forms the major physiological anticoagulant pathway. Agkistrodon contortrix contortrix protein C activator, a glycosylated single-chain serine proteinase, activates protein C without relying on thrombomodulin. The crystal structures of native and inhibited Agkistrodon contortrix contortrix protein C activator determined at 1.65 and 1.54 A resolutions, respectively, indicate the pivotal roles played by the positively charged belt and the strategic positioning of the three carbohydrate moieties surrounding the catalytic site in protein C recognition, binding, and activation. Structural changes in the benzamidine-inhibited enzyme suggest a probable function in allosteric regulation for the anion-binding site located in the C-terminal extension, which is fully conserved in snake venom serine proteinases, that preferentially binds Cl(1-) instead of SO(4)(2-). Thrombomodulin-independent activation of protein C and specificity of hemostatically active snake venom serine proteinases: crystal structures of native and inhibited Agkistrodon contortrix contortrix protein C activator.,Murakami MT, Arni RK J Biol Chem. 2005 Nov 25;280(47):39309-15. Epub 2005 Sep 14. PMID:16162508[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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