(A) Isoleucylation of total E. coli tRNAs by wild-type and editing-defective (T252Y) E. coli LeuRS variants at 2°C (8 μM enzyme) or 37°C (2.4 μM enzyme, inset) ± 10 μM activated E. coli EF-Tu.
(B) Hydrolysis of 0.5 μM Ala-tRNAPro at 37°C ± EF-Tu, 2.5 μM EcProRS, and 10 μM activated E. coli EF-Tu. Pro-tRNAPro was previously shown to be stable under these conditions (Beuning and Musier-Forsyth, 2000).
Error bars correspond to the standard deviation from three independent experiments.