Fig. 3.

(A) Overlay of CYP2B35 (green) and CYP2B37 (magenta) structures showing closed and open conformations, respectively. The 4-CPI molecules in the CYP2B35 structure are shown as orange sticks, and those in the 2B37 structure, as blue sticks. Substrate access channel 2f is shown in pale yellow extending to the protein surface from heme. (B) Active site of the CYP2B35 structure (green) showing residues located within 5 Å from either 4-CPI molecule (orange sticks). A total of 19 residues that include A363 and A367 are shown, constituting the active site of CYP2B35. (C) The residues that comprise the active site in the CYP2B37 structure (magenta) within 5 Å from the 4-CPI (blue) coordinating heme are I101, V114, F115, F297, A298, G299, T302, I363, and V367, represented as sticks. The residues within 5 Å from the second and third 4-CPI molecules located in the access channel are also shown as sticks. (D) Alternate orientation and rearrangement of F206 and F297 side chains in the CYP2B35 (green) and CYP2B37 (magenta) structures are represented as sticks. The reorientation of the 4-CPI toward the I helix and the adjacent molecule in the CYP2B35 active site are shown as orange sticks. The 4-CPI molecules, one located within the active site and the other at the periphery, in the CYP2B37 structure are shown in blue.