Table 2.
Apparent rates of pseudouridine formation by TruB variants
| TruB | kapp, s−1 | Fold decrease |
|---|---|---|
| Wild type | 0.5 ± 0.2 | |
| D90E | 0.017 ± 0.003 | 30 |
| D90N | 0.010 ± 0.003 | 50 |
| D90A | 0.0010 ± 0.0002 | 500 |
| R181K | 0.0002 ± 0.0001 | 2500 |
| R181M | < 3 × 10−5 | >20 000 |
| R181A | <3 × 10−5 | >20 000 |
Apparent rates, kapp, were determined by single-exponential fitting of time courses recorded under single-turnover conditions (Figure 4). The fold decrease in catalytic rate is given relative to the rate constant of pseudouridine formation by TruB wild type as previously determined (30). kapp represents average rate from duplicate data ± standard deviation.