Unbiased σA weighted |Fo| − |Fc| electron density for the R,S-BIC complex of CYP46A1 at 2.1 Å resolution contoured from 3σ to 5σ in intervals of 1σ. BIC carbon atoms are white, oxygen atoms are red, nitrogen atoms are blue, fluorine atoms are purple, and sulfur atoms are cyan; heme carbon atoms are orange; Cα atoms of the I-helix are yellow. Both BIC isomers are shown.