TABLE 2.
Observed rate constants of EcLeuRS and its mutants in AMP synthesis at 37 °C
Rates were determined using the AMP formation in the TLC assay described under “Experimental Procedures.” All rates represent the average of three trials with the S.D. indicated.
| LeuRS | tRNA | AN2690 | AMP formation kobs |
|---|---|---|---|
| s−1 | |||
| WT | − | − | (3.3 ± 0.4) × 10−1 |
| WT | + | − | 3.42 ± 0.51 |
| WT | − | + | (3.1 ± 0.4) × 10−1 |
| WT | + | + | 1.86 ± 0.28 |
| T252R | − | − | (3.5 ± 0.6) × 10−1 |
| T252R | + | − | 1.53 ± 0.27 |
| Y330D | − | − | (3.6 ± 0.53) × 10−1 |
| Y330D | + | − | (3.9 ± 0.63) × 10−1 |
| T252A/Y330D | − | − | (3.7 ± 0.56) × 10−1 |
| T252A/Y330D | + | − | (4.4 ± 0.72) × 10−1 |