Table 2.
Insertion/misinsertion of dNTPs opposite 8-oxo-dG by wild-type exo- and the Y955C pol γ
| Enzyme | dG in the template | 8-oxo-dG in the template | ||||||
|---|---|---|---|---|---|---|---|---|
| Km (μM) | kcat (min −1) | kcat/Km (min μM)−1 | DFa | Km (μM) | kcat (min −1) | kcat/Km (min μM)−1 | DFa | |
| Wild-type | ||||||||
| A | 41.8 (±9.2) | 0.07 (±0.01) | 0.018 | 1.7×l04 | 54.0 (±5.3) | 0.31 (±0.06) | 0.0057 | 2.2×103 |
| T | 18.7 (±3.7) | 0.18 (±0.02) | 0.096 | 3.3×103 | 76.0 (±12.4) | 0.069 (±0.01) | 0.0009 | 1.6×104 |
| C | 0.02 (±0.004) | 6.1 (±1.7) | 305 | 1 | 0.3 (±0.02) | 4.3 (±0.2) | 14.3 | 1 |
| G | 53.1 (±10.2) | 0.53 (±0.06) | 0.01 | 3.0×104 | 62 (±5.4) | 0.43 (±0.08) | 0.0069 | 2.1×103 |
| Y955C | ||||||||
| A | 232 (±21.5) | 0.51 (±0.07) | 0.0022 | 33 | 280 (±15.0) | 0.34 (±0.02) | 0.0012 | 24 |
| T | 303 (±17.3) | 0.14 (±0.02) | 0.0005 | 150 | 1530 (±171) | 0.08 (±0.01) | 0.00005 | 590 |
| C | 6.2 (±0.61) | 0.46 (±0.05) | 0.074 | 1 | 18 (±2.7) | 0.52 (±0.07) | 0.029 | 1 |
| G | 257 (±35.3) | 0.19 (±0.03) | 0.0007 | 105 | 350 (±41.5) | 0.20 (±0.03) | 0.00057 | 50 |
a
DF, discrimination factor (kcat/Km)correct dNTP/(kcat/Km)incorrect dNTP; values compared within each of the following categories: (i) exo- wt p140 utilizing G template, (ii) exo- wt p140 utilizing 8-oxo-dG template, (iii) exo-Y955C utilizing G template and (iv) exo-Y955C utilizing 8-oxo-dG template. All reactions were done in the presence of the accessory subunit.