Figure 2.
Deacylation of mischarged Hs cytosolic Ala-tRNAPro by Hs ProXp-ala under single-turnover conditions. A, time course of Ala-tRNAPro deacylation with varying concentrations (0.75, 1.0, 1.5, 2.0, 3.0, 4.0, 6.0, 8.0, and 12 μm) of Hs ProXp-ala. The reactions were performed with 100 nm Hs Ala-tRNAPro at 30 °C. Deacylation curves were fit to a single exponential equation. B, hyperbolic fit of the observed rate constant versus Hs ProXp-ala concentration yielded a kmax of 3.8 min−1 and a Kd, app of 10.2 μm. The results are based on a single experiment at each enzyme concentration.