Domain Architecture
Factors VII, IX, and X all play key roles in blood coagulation and also share a common domain architecture. The factor IX protein is composed of four protein domains. These are the Gla domain, two tandem copies of the EGF domain and a C-terminal trypsin-like peptidase domain which carries out the catalytic cleavage.
The N-terminal EGF domain has been shown to at least in part be responsible for binding Tissue factor. Wilkinson et al. conclude that residues 88 to 109 of the second EGF domain mediate binding to platelets and assembly of the Factor X activating complex.
The structures of all four domains have been solved. A structure of the two EGF domains and trypsin like domain was determined for the pig protein. The structure of the Gla domain, which is responsible for Ca(II)-dependent phospholipid binding, was also determined by NMR.
Several structures of 'super active' mutants have been solved which reveal the nature of Factor IX activation by other proteins in the clotting cascade.
Read more about this topic: Factor IX
Famous quotes containing the words domain and/or architecture:
“No domain of nature is quite closed to man at all times.”
—Henry David Thoreau (1817–1862)
“The two elements the traveler first captures in the big city are extrahuman architecture and furious rhythm. Geometry and anguish. At first glance, the rhythm may be confused with gaiety, but when you look more closely at the mechanism of social life and the painful slavery of both men and machines, you see that it is nothing but a kind of typical, empty anguish that makes even crime and gangs forgivable means of escape.”
—Federico García Lorca (1898–1936)