Distribution of the different S states (% of the total PSII amount) in EPR samples after the application of 0–6 turnover flashes given at frequency of 5 Hz and 10 Hz at 20 °C (see ESI Fig. 2)^a.

Fl. freq.	Fl. no.	S1	S2	S3	S0	S1(2nd)	S2(2nd)	S3(2nd)	Total
5 Hz	0	100							100
	1	10	90						100
	2		29 ± 1	71 ± 2					100
	3		11 ± 3	23 ± 1	66 ± 1				100
	4		10 ± 3	10 ± 1	22 ± 2	58 ± 1			100
	5			4 ± 1	9 ± 1	26 ± 1	62 ± 1		101
	6				6 ± 1	7 ± 1	38 ± 1	46 ± 3	97
10 Hz	0	100							100
	1	10	90						100
	2		33 ± 2	64 ± 1					97
	3		17 ± 2	26 ± 1	57 ± 1				100
	4		15 ± 1	7 ± 1	28 ± 1	49 ± 2			99
	5			3 ± 1	9 ± 1	30 ± 2	58 ± 2		100
	6				3 ± 1	14 ± 1	39 ± 2	42 ± 1	99

^aThe fraction of the S_i – state was determined from the EPR spectra as described in the text and in ref. 40.