title: Crystal structure of the factor XI zymogen reveals a pathway for transactivation.
abstract: Factor XI (FXI), a coagulation protein essential to normal hemostasis, circulates as a disulfide-linked dimer. Here we report the full-length FXI zymogen crystal structure, revealing that the protease and four apple domains assemble into a unique 'cup and saucer' architecture. The structure shows that the thrombin and platelet glycoprotein Ib binding sites are remote within the monomer but lie in close proximity across the dimer, suggesting a transactivation mechanism.
authors.affiliation: Centre for Biomolecular Sciences, School of Pharmacy, University of Nottingham, Nottingham, NG72RD, UK.
authors.forename: Evangelos
authors.initials: E
authors.lastname: Papagrigoriou
authors.forename: Paul A
authors.initials: PA
authors.lastname: McEwan
authors.forename: Peter N
authors.initials: PN
authors.lastname: Walsh
authors.forename: Jonas
authors.initials: J
authors.lastname: Emsley
mesh_terms: D018360:Crystallography, X-Ray; D004792:Enzyme Precursors / Q000737:chemistry*; D005172:Factor XI / Q000737:chemistry*; D008958:Models, Molecular; D015533:Transcriptional Activation
chemical_list: D004792:Enzyme Precursors; D005172:Factor XI