2WPL: Factor Ixa Superactive Triple Mutant, Edta-soaked

Human coagulation factor IX serves both to maintain and to control blood coagulation. The dual function of this hemophilic factor is implemented by a tiered activation mechanism. Processed two-chain factor IXa is catalytically silent; only together with its cofactor VIIIa does factor IXa form the highly potent Xase complex. The detailed mechanism of this secondary activation has remained elusive so far. Here we present the crystal structures of Xase-like factor IXa mutants with several-thousand-fold activity enhancement that mimic the secondary activation by Xase formation. The structures reveal how cofactor-triggered and substrate-assisted modulations in the factor IXa 99- and 60-loops cooperate in S4 through S2' formation, allowing for productive substrate recognition. We could further physically map and visualize a distinct communication line, along which agonists such as Ca(2+) direct their effects to the active site and vice versa.
PDB ID: 2WPLDownload
MMDB ID: 78845
PDB Deposition Date: 2009/8/6
Updated in MMDB: 2016/12
Experimental Method:
x-ray diffraction
Resolution: 1.82  Å
Source Organism:
synthetic construct
Similar Structures:
Biological Unit for 2WPL: trimeric; determined by author and by software (PISA)
Molecular Components in 2WPL
Label Count Molecule
Proteins (3 molecules)
Coagulation Factor IXA Light Chain(Gene symbol: F9)
Molecule annotation
Coagulation Factor IXA Heavy Chain(Gene symbol: F9)
Molecule annotation
D-phe-pro-arg-chloromethyl Ketone
Molecule annotation
* Click molecule labels to explore molecular sequence information.

Citing MMDB