Fig. 6.

Homology model of C. rosea S8A serine protease BN869_T00009071 (PRS16), a propeptide (teal) and catalytic domain (blue) shown in the cartoon and highly variable regions are highlighted with colour in 6A to 6C figures. Variable region II is shown in red, region III in green, region IV in magenta, region V in yellow, region VI in orange and region VII in gold. Catalytic triad residues are shown in white stick representation, Ca²⁺ ligands (imported from PDB ID: 1IC6) shown as pink spheres and a peptide ligand (imported from PDB ID: 2HPS) is shown in rainbow coloured sticks. a shows a cartoon representation of the full protein, with the propeptide (teal) extending into the active site. Variable regions can be seen residing on surface accessible loops of the catalytic domain (blue). b shows a cartoon representation of the catalytic domain and peptide ligand, rotated 90° in regards to A and highlights the positions of regions III, V and VII which are located further away from the active site region. Region V comprises most of calcium-binding site 1 and VII is close and contributes a stabilising sulfhydryl bond to the calcium binding pocket. The active site is seen occupied by a ligand peptide molecule. c shows a surface representation of the catalytic domain with a ligand peptide, shown in rainbow coloured sticks, bound to the active site cleft and highlights the close positions of regions II, IV and VI to the active site cleft