Table 2. The distances of the steroid side-chain carbons from the heme iron. The pro-R and pro-S C-26 atoms are distinguished by labels in Fig. S20†.

	Fe–C distance (Å)
C#	CYP125	CYP125	CYP125A1
	MRCA	MRCA	Cholest-4-
	Sitosterol	Vitamin D3	en-3-one
25	4.5 ± 0.17	4.5 ± 0.12	5.1 ± 0.07
Pro-S C-26	4.8 ± 0.18	4.9 ± 0.12	4.3 ± 0.08
Pro-R C-26	4.6 ± 0.17	4.0 ± 0.12	4.8 ± 0.08