TABLE 1.

Apparent reaction rates and Arrhenius parameters of NpSRII at various temperatures, in detergent (0.1% DDM) or in membranes, and in the absence or presence of transducer

	WT NpSRII				WT NpSRII + NpHtrII				LT NpSRII
	Detergent		PML		Detergent		PML		Detergent
	Dark	Light	Dark	Light	Dark	Light	Dark	Light	Dark	Light
°C	Reaction rates (×10−3/s)*
20	2.2	58		48	2.3			70
25	3.5	58	3.6	49	3.3	49	4.0	70	0.23	0.82
30	6.4	60	4.9	72	4.6	61	5.6	69	0.45	0.92
35	8.5	57	8.0	74	7.2	72	9.1	65	1.2	1.4§
40			13			78	14.6		1.5	1.9
Arrhenius parameters
A†	8.0×109	5.7×10−2	1.8×109	1.5×103	2.7×107	8.2×102	2.2×109	2.0×10−2	2.9×1014	3.6×104
Ea‡	16.9	0	16.0	6.0	13.5	5.7	16.0	0	24.6	10.5

^*Error in reaction rates is in the last significant digit.

^†Frequency factor (s⁻¹). Error is ∼10%.

^‡Activation energy (kcal/mol). Error is ∼10%.

^§Since the rate of the light reaction was very similar to that of the dark reaction, a monophasic scheme was used to calculate the rate, whereas in all other cases, the light reaction rate was calculated using a biphasic scheme (see Materials and Methods).