Table 1. Definition of iron sites.

Data collection
Dataset	FEHR	FE0	FE30	FE120
Refinement statistics (cns/refmac)
Iron content*	Low (0 min)	Low (0 min)	High (30 min)	High (120 min)
No. of irons in TS†	0	0	3 (T1-T3)	3 (T1-T3)
No. of irons in FOC†	1 (F1)	1 (F1)	3 (F1-F3)	1 (F1)
No. of irons in NI†	0	0	3 (N11-N13)	3 (N11-N13)
No. of irons in NII†	1 (N21)	1 (N21)	5 (N21-N25)	5 (N21-N25)

^*Incubation time of crystals with Fe²⁺ solutions is given in parentheses.

^†Definition of the subsites used in the text is given in parentheses.