Figure 5. The location of residues in tertiary structure space for heme ligands (H24, H339), electron transfer pathway residues (F338, R400, R401), Mg ligands (H329), CuB ligands (H186, H235, H236), proton pathway residues (Y190, T262). Figure 5a shows an overall view of the structure (line trace back-bone) with the above residue positions highlighted as sticks. Figure 5b is a magnification of the residue positions in structure space.