TABLE 2.
Kinetic constants for ATP hydrolysis for WT and mutated LTAgsa
| Protein | kcat (min−1) | Km (μM) | ssDNA stimulation (fold)b |
|---|---|---|---|
| WT | 20 ± 1 | 270 ± 40 | 7.8 ± 1.4 |
| tK418A mutant | 2.8 ± 0.3 | 110 ± 30 | 1.4 ± 0.2 |
| tK419A mutant | 14 ± 1 | 280 ± 50 | 3.2 ± 0.5 |
| tR498A mutant | 6.6 ± 1.7 | 400 ± 200 | 5.1 ± 0.3 |
| tD499A mutant | 3.3 ± 0.5 | 80 ± 40 | 12.2 ± 0.6 |
| tD502A mutant | 0.60 ± 0.04 | 30 ± 7 | 1.5 ± 0.3 |
| tR540A mutant | 0.70 ± 0.10 | 170 ± 60 | 2.2 ± 0.3 |
| cD474A mutant | 0.70 ± 0.10 | 80 ± 30 | 1.4 ± 0.2 |
| cT527A mutant | 12 ± 0.8 | 50 ± 10 | 7.1 ± 1.2 |
| cN529A mutant | 1.8 ± 0.3 | 120 ± 50 | 1.6 ± 0.4 |
a
Michaelis-Menten kinetic constants for WT and mutated LTAgs in the absence of ssDNA. The data were generated as described in reference 17 and were an average of at least four independent experiments.
b
ssDNA stimulation is defined as the ratio of the amount of ATP hydrolyzed by a given protein in the absence of ssDNA versus that hydrolyzed by the same protein in the presence of a saturating concentration of ssDNA.