Figure 4.
CYP17A1 X-ray structures with abiraterone analogs. Abiraterone analogs bearing (A) a C6 nitrile (7; green, 6CIZ), (B) a C6 amide (8; cyan, 6CHI), and (C) a C6 oxime (13b; magenta, 6CIR) and key residues are shown as sticks. Interactions that fit the criteria for hydrogen bonding are indicated by dashed lines. Blue mesh represents the |2Fo|-|Fc| electron density maps of the ligands contoured at 1.0 σ. The heme is shown as black sticks with its iron as an orange sphere. Notably the N202 side chain can be a hydrogen bond donor (A) or acceptor (B and C), as can the C3 hydroxyl.
