Figure 2. Editing of seryl-tRNA^Ala with AlaRS WT and editing mutants.

Measurements of editing initial rates with AlaRS WT, T567G, and E664A versus [seryl-tRNA^Ala] were fit to the Michaelis-Menten equation, whereas data obtained with AlaRS Q584H, C666A and I677E were fit by linear regression. The resulting k_cat, K_M, and/or k_cat/K_M parameters are reported in Table 1. The rates shown represent an average of 2–4 independent measurements. Error bars, when shown represent the standard of at least three independent measurements. When no errors bars are shown, each rate represents the average of at two independent experiments, with a variance of no more than 25%.