TABLE 3.
Pre-steady-state kinetic parameters for dTMP, d4TMP, and 4′-Ed4TMP incorporation by wt RT and the M184V mutant with DNA/DNA and DNA/RNA P/Ts
| P/T | Enzyme | dTTP
|
d4TTP
|
4′-Ed4TTP
|
||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Kd(μM) (mean ± SD) | kpol(s−1) (mean ± SD) | kpol/Kd (μM−1 s−1) | Kd(μM) (mean ± SD) | kpol(s−1) (mean ± SD) | kpol/Kd (μM−1 s−1) | Selectivitya | Kd(μM) (mean ± SD) | kpol(s−1) (mean ± SD) | kpol/Kd (μM−1 s−1) (mean ± SD) | Selectivitya | ||
| DNA/DNA | wt RT | 15.4 ± 2.9 | 22.6 ± 1.3 | 1.47 | 48.0 ± 4.8 | 16.0 ± 0.5 | 0.33 | 4.5 | 15.8 ± 2.4 | 12.1 ± 0.5 | 0.77 | 1.9 |
| M184V | 73.2 ± 8.0 | 22.4 ± 0.9 | 0.31 | 605 ± 285 | 29.8 ± 10.4 | 0.05 | 6.2 | 168.1 ± 25.6 | 18.9 ± 1.1 | 0.11 | 2.8 | |
| DNA/RNA | wt RT | 67.1 ± 10.2 | 65.0 ± 3.9 | 0.97 | 40.8 ± 9.2 | 18.4 ± 1.4 | 0.45 | 2.2 | 11.4 ± 2.7 | 11.7 ± 0.8 | 1.0 | 0.97 |
| M184V | 143.9 ± 25.0 | 41.7 ± 3.5 | 0.29 | 232.3 ± 50.0 | 29.6 ± 3.6 | 0.13 | 2.2 | 43.4 ± 13.9 | 9.7 ± 0.8 | 0.22 | 1.3 | |
a
Selectivity is calculated by dividing the efficiency of dTTP (kpol/Kd) by the efficiency of d4TTP or 4′-Ed4TTP.