Sequence motifs surrounding the axial ligands. (A) Sequence logo from 32 heme c proteins with histidine as axial ligand shows the classic CXXCH heme c binding motif; (B) Sequence logo from 18 heme b proteins with cysteine as axial ligand. The sequence logos were created with WebLogo ; (C) Arginine-334 (red sticks) of 1N97A interacts with heme propionates (red spheres); and (D) Interactions between histidine-353 (red sticks) of 1GWIA and heme propionate groups (red spheres).
Li et al. BMC Structural Biology 2011 11:13 doi:10.1186/1472-6807-11-13