Figure 8.

The arrangement of the active-site acidic residues, based on distance between residues, indicates that the shape of the calcium-binding site plays a role in the affinity for calcium ions and ligand. The acidic residues of the calcium-binding site of (a) B. subtilis PL1 and (b) C. bescii PL3 are shown in stick form, with calcium ions shown as grey spheres and the backbone shown in cartoon representation. Distances between the C^α atoms for each residue are shown, indicating the shape and distance of the acidic residues comprising the calcium-binding sites.