Fig. 2.

Numerous human endogenous pathways include one or more cytochrome P450 enzymes. Those for which structures of the human enzyme are known are in red; those with structures of mammalian homologs are in blue; while those without structures are in black. Lower right inset, structure of CYP17A1 with the prostate cancer drug abiraterone (gray sticks) above the heme prosthetic group (black sticks) displays the common P450 structural elements colored from the N-terminus (blue) to the C-terminus (red).