TABLE 3.
Steady-state kinetic parameters of extension from primers paired opposite m6G and 8-oxoG catalyzed by human Pol ι
| Template:primer base pair | Incoming nucleotide | kcat (min−1) | Km (μM) | kcat/Km | foextc |
|---|---|---|---|---|---|
| G:G | T | NDa | ≥500 | 2.0 × 10−5 | 7.1 × 10−5b |
| G:A | T | 0.052 ± 0.007 | 180 ± 30 | 2.9 × 10−4 | 1 × 10−3 |
| G:T | T | 0.63 ± 0.07 | 46 ± 6 | 1.4 × 10−2 | 5 × 10−2 |
| G:C | T | 2.1 ± 0.2 | 7.4 ± 0.5 | 0.28 | 1 |
| m6G:G | T | ND | ≥500 | 1.0 × 10−5 | 3.6 × 10−5b |
| m6G:A | T | 0.065 ± 0.009 | 140 ± 30 | 4.6 × 10−4 | 1.6 × 10−3 |
| m6G:T | T | 2.4 ± 0.14 | 38 ± 3 | 6.3 × 10−2 | 0.23 |
| m6G:C | T | 0.75 ± 0.04 | 130 ± 15 | 5.8 × 10−3 | 2 × 10−2 |
| 8-oxoG:G | T | 0.028 ± 0.004 | 190 ± 40 | 1.5 × 10−4 | 5.4 × 10−4 |
| 8-oxoG:A | T | 2.3 ± 0.1 | 13 ± 2 | 0.17 | 0.6 |
| 8-oxoG:T | T | 0.083 ± 0.009 | 180 ± 20 | 4.6 × 10−4 | 1.6 × 10−3 |
| 8-oxoG:C | T | 0.33 ± 0.05 | 110 ± 13 | 3.0 × 10−3 | 1.1 × 10−2 |
a
ND, not determined.
b
Because the nucleotide incorporation rate remained linear throughout the nucleotide concentration range used, the kcat/Km value was obtained from the slope of the line.
c
foext depicts the efficiency of extension of different primer termini relative to the extension from a G:C base pair.