Table 1.

The normalized rates of Meta II decay and transducin activation of Tyr136^3.51, Tyr223^5.58, Tyr306^7.53, and Ala132^3.47 mutants at 20 °C

	Meta II decay (n = 3)		Transducin activation (n = 2)
	Half-life, min	Normalized decay rate, % of wild type	Normalized initial rate, % of wild type	Normalized fluorescence increase, % of wild type
Wild-type	14.8 ± 0.3*	100 ± 2.1*	100 ± 7.1*	100 ± 4.1*
Y136F	12.5 ± 0.9	118 ± 8.6	149 ± 16.9	106 ± 3.4
Y223F	3.2 ± 0.2	466 ± 29.0	6 ± 1.5	5 ± 2.9
Y306F	10.5 ± 0.6	140 ± 8.1	84 ± 7.4	72 ± 2.2
A132L	3.8 ± 0.3	386 ± 31.0	69 ± 1.2	34 ± 6.2
A132S	9.3 ± 1.2	159 ± 20.9	31 ± 8.2	63 ± 2.8

^*Mean ± standard error.