TABLE 1.
Deletion of the Rpb9 subunit confers a 5-fold decrease in fidelity of transcription in vitro
TEC9 was assembled on the template 65 and chased with 0.01–1 mm CTP or 0.1–2 mm UTP. The kpol and KD parameters were obtained from the hyperbolic fit as described in the supplemental text. The fidelity parameter in the last column (bold) for the WT and pol IIΔ9 is determined by dividing kpol/KD for the correct CTP and kpol/KD for the incorrect UTP.
| pol II variant | NTP | kpol | KD | kpol/KD | Fidelity |
|---|---|---|---|---|---|
| s−1 | μm | s−1μm−1 | |||
| WT | CTP (correct) | 75 ± 4 | 68 ± 7 | 1.1 ± 0.2 | |
| UTP (incorrect) | (7.8 ± 0.9) × 10−3 | 3531 ± 556 | (2.2 ± 0.6) × 10−6 | (5 ± 2.1) × 105 | |
| rpb9 | CTP (correct) | 60.5 ± 4.6 | 76.1 ± 19.1 | 0.8 ± 0.2 | |
| UTP (incorrect) | (20 ± 3.9) × 10−3 | 2860 ± 792 | (6.9 ± 3) × 10−6 | (1.1 ± 0.6) × 105 |