Superimposition of C. albicans CYP51 and A. fumigatus CYP51B (PDB code 4UYL) complexes with posaconazole (cyan) and VNI (blue), respectively. The heme (gray), posaconazole, and VNI are depicted as spheres; the binding cavity-forming residues, conserved in both proteins, are shown in stick representation and labeled.