English: Crystallographic structure of cytochrome P450 from the bacteria S. coelicolor (rainbow colored cartoon, N-terminus = blue, C-terminus = red) complexed with heme cofactor (magenta spheres) and two molecules of its endogenous substrate epi-isozizaene as orange and cyan spheres respectively. The orange colored substrate resides in the monooxygenase site while the cyan colored substrate occupies the substrate entrance site. An unoccupied moonlighting terpene synthase site is designated by the arrow.^[1]