Table 2.

Single-turnover deamination kinetics of ADAR2-R2D E488Q and dimerization mutants on D-site of the 5-HT_2c-R substrate^a.

Enzymeb	k obs (min−1)c	k rel d
ADAR2-R2D E488Q	2.13 ± 0.30	1
ADAR2-R2D E488Q, T501A	>3	-
ADAR2-R2D E488Q, W502A	0.12 ± 0.03	0.056
ADAR2-R2D E488Q, D503A	2.32 × 10−3 ± 0.76 × 10−3	0.001

^a5-HT_2c pre-mRNA substrate sequence as shown in Supplementary Table S1.

^bADAR2-R2D reactions were carried out with 100 nM enzyme, 10 nM RNA substrate in 17 mM Tris pH 7.4, 60 mM KCl, 15.6 mM NaCl, 1.6 mM EDTA, 0.003% Nonidet P-40, 0.5 mM DTT, 1.0 μg/ml yeast tRNA (Torula), 160 units/ml RNasin.

^c k _obs was calculated by fitting the time course 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.

^d k _rel = k_obs for mutant/k_obs for ADAR2-R2D E488Q.