Factor Xa: Difference between revisions

The members of the trypsin-like serine protease family have two homologous greek key β-barrel subdomains (<scene name='Factor_Xa/Transparent_-no_inhib-_barrel1/1'>barrel 1</scene>, <scene name='Factor_Xa/Transparent_-_no_inhib_barrel2/1'>barrel 2</scene>) in the heavy chain. The greek key barrel is characterized as an up and down β-barrel with an n+3 linkage across the barrel, in this case, the across barrel linkage is an α-helix. The <scene name='Factor_Xa/Transparent_-no_inhib-_barrels/1'>two barrels</scene> pack together asymmetrically to constitute the compact <scene name='Factor_Xa/Transparent_-_barrels_catalyt/1'>catalytic domain</scene>. The subdomain interface forms the active site with the substrate binding cleft running along the subdomain boundary. Notably, the conserved catalytic tetrad residues Ser195, His57, Asp102, and Ser214 are from the C-, N-, N-, and C-terminal domains, respectively. Although the hydrophobic core structures remain conserved throughout the family (12), considerable variation is seen in the surface loops, especially surrounding the active site where they determine substrate specificities