TABLE 2.
Enzyme | kcata | Kmb | kcat/Km |
---|---|---|---|
s−1 | μm | ||
gp43c | 0.61d | 0.49 | 1.25 |
A | 0.39 | 0.92 | 0.42 |
A/V781I | 0.51 | 0.92 | 0.55 |
ABC | 0.46 | 2.7 | 0.17 |
ABC/R784A | 0.39 | 3.3 | 0.12 |
ABC/Q807A | 0.50 | 3.6 | 0.14 |
a kcat is the enzyme turnover number that is calculated by normalizing the maximum velocity of the reaction to the enzyme concentration.
b Km is the substrate concentration at half-maximum velocity of the reaction.
c The previously reported gp43 values for dCTP kcat and Km are 1.0 s−1 and 0.57 μm, respectively (51).
d Standard deviations were determined on the basis of at least three independent experiments and represent a maximum of 12% of the reported value.