2aiq
| |||||||
| , resolution 1.54Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | , , , , , and | ||||||
| Activity: | Venombin A, with EC number 3.4.21.74 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
Crystal structure of benzamidine-inhibited protein C activator from the venom of copperhead snake Agkistrodon contortrix contortrix
OverviewOverview
Protein 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-).
About this StructureAbout this Structure
2AIQ is a Single protein structure of sequence from Agkistrodon contortrix contortrix. Full crystallographic information is available from OCA.
ReferenceReference
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
Page seeded by OCA on Thu Mar 20 15:50:11 2008