Table 2.

Adenosine deamination rate constants measured under single-turnover conditions for ADAR1 R3D and AGS mutants on hGli1 and 5-HT_2cR B site RNAs^a.

Substrate	Enzyme	k obs (min −1 ) b	k rel c
Gli1	ADAR1 R3D	1.7 ± 0.2	1
	ADAR1 R3D, G1007R	0.07 ± 0.01	0.04
	ADAR1 R3D, K999N	0.4 ± 0.1	0.2
	ADAR1 R3D, R892H	0.3 ± 0.1	0.2
	ADAR1 R3D, Y1112F	1.3 ± 0.2	0.7
5-HT2c	ADAR1 R3D	0.05 ± 0.01	1.0
	ADAR1 R3D, G1007R	-	-
	ADAR1 R3D, K999N	-	-
	ADAR1 R3D, R892H	-	-
	ADAR1 R3D, Y1112F	0.04 ± 0.01	0.8

^ahGli1 and 5-HT_2cR pre-mRNA substrate sequences are shown in Table S1. ADAR1 R3D reactions were carried out with 15 mM Tris–HCl pH 7.5, 26 mM KCl, 40 mM potassium glutamate, 1.5 mM EDTA, 0.003% (v/v) NP-40, 4% (v/v) glycerol, 0.5 mM DTT, 1 μg/mL yeast tRNA, and 0.16 U/μL RNAse inhibitor.

^bk_obs was calculated by fitting fitting product formed at different time points to the equation: [P]_t = α[1 −e^−kobst] where [P]_t is percent edited, α is the end point fitted to 95%, and k_obs is the observed rate constant.

^ck_rel = k_obs for mutant/k_obs for ADAR1 R3D.