Table 2. Efficiency of tRNA^Val variants in stimulating translational editing.

tRNAVal variant	Relative rate of ATP hydrolysisa	Relative aminoacylation efficiencyb (Vmax/Km)
Wild-type (UAC)	(1.0)	(1.0)
(A) Acceptor stem mutants
U4:A69→G4:U69	0.18	0.026
U4:A69→U4:G69	0.45	0.17
(B) Anticodon stem mutants
U29:A41→C29:G41	–0.04	0.022
(C) Anticodon mutants
A35→G35	0.05	7.5 × 10–6
C36→U36	0.07	8.6 × 10–4
(D) Central core mutants
G45→U45	0.62	0.57
G45→A45	0.49	0.48
No tRNA	–0.08	–

^aNegative values are the result of small changes in the background rate of ATP hydrolysis.

^bResults are from Liu et al. (22) and Horowitz et al. (23); included for comparison.