TABLE 2.

Computed E_m(Y_Z/D) in [mV] at pH 7.0

Redox couple	Mn-cluster S-state	Em(YZ)	Em(YD)
Y˙/Y−*	S0	+932	+686
	S1	+931	+689
	S2	+926	+694
	S3	+959	+702
	Mn-depleted†	+780	+685
Y˙+/Y*	S2	+1669	+1907

^*For the E_m values used as reference model system, see Tommos and Babcock (10).

^†All the titratable groups in PSII were titrated, as was done in computations with intact Mn-cluster.