Table 1.
Summary of readthrough and growth data for eRF1 variants used in this study
| Growth¥ |
Percent readthrough† |
eRF3 dependence for release activity |
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Type of eRF1 | Mutations | 22°C | 30°C | 35°C | UAA | UAG | UGA | UAA | UAG | UGA |
| Eo/Sc eRF1 | WT | − | − | − | 0.32±0.03 | 0.69±0.07 | 10.70±0.69 | YES | YES | nr |
| Eo/Sc eRF1 | C124S | − | +/− | + | 0.40±0.06 | 0.17±0.04 | 0.14±0.004 | YES | YES | YES |
| Eo/Sc eRF1 | C124N | − | + | + | 0.32±0.04 | 0.20±0.03 | 0.12±0.02 | nd | nd | nd |
| Eo/Sc eRF1 | A75S | − | + | ++ | 0.13±0.02 | 0.17±0.02 | 0.86±0.13 | nd | nd | nd |
| Eo/Sc eRF2 | A75S/C124S | +/− | + | ++ | nd | nd | nd | nd | nd | nd |
| Eo/Sc eRF1 | A75S/C124N | − | ++ | +++ | 0.22±0.05 | 0.29±0.04 | 0.11±0.02 | nd | nd | nd |
| Eo/Sc eRF1 | E57S | − | − | − | nd | nd | nd | nd | nd | nd |
| Eo/Sc eRF1 | S58N | − | − | − | nd | nd | nd | nd | nd | nd |
| Eo/Sc eRF1 | E57S/S58N | − | +/− | ++ | 0.24±0.07 | 0.20±0.04 | 0.71±0.11 | NO | NO | YES |
| Eo/Sc eRF1 | E57S/C124S | − | + | +++ | nd | nd | nd | nd | nd | nd |
| Eo/Sc eRF1 | S58N/C124S | − | ++ | +++ | nd | nd | nd | nd | nd | nd |
| Eo/Sc eRF1 | E57S/S58N/C124S | ++ | +++ | +++ | 0.15±0.01 | 0.15±0.01 | 0.18±0.02 | nd | nd | nd |
| Eo/Sc eRF1 | E57S/S58N/A75S | + | ++ | +++ | nd | nd | nd | nd | nd | nd |
| Eo/Sc eRF1 | E57S/S58N/CΔ19 | − | +/− − | +/− | 0.14±0.01 | 0.16±0.02 | 6.9±0.51 | NO | NO | YES |
| Sc eRF1 | WT | +++ | ++++ | ++++ | 0.26±0.02 | 0.14±0.01 | 0.39±0.06 | YES | YES | YES |
| Sc eRF1 | C124S | ++ | +++ | +++ | 0.34±0.04 | 0.22±0.03 | 0.17±0.03 | nd | nd | nd |
| Sc eRF1 | S57E | + | ++ | ++ | 0.19±0.02 | 0.22±0.02 | 1.04±0.04 | nd | nd | nd |
| Sc eRF1 | N58S | + | ++ | ++ | 0.34±0.02 | 0.19±0.01 | 0.93±0.11 | nd | nd | nd |
| Sc eRF1 | S57E/N58S | +/− | + | ++ | 0.18±0.01 | 0.20±0.02 | 0.80±0.05 | nd | nd | nd |
| Sc eRF1 | depleted | − | − | − | 5.27±0.54 | 4.68±0.08 | 18.36±2.10 | nd | nd | nd |
| Sc eRF1 | S57E/C124S | − | − | − | 0.58±0.07 | 1.13±0.05 | 0.62±0.04 | nd | nd | nd |
| Sc eRF1 | N58S/C124S | − | − | − | 5.07±0.57 | 4.78±0.58 | 0.58±0.10 | nd | nd | nd |
| Sc eRF1 | S57E/N58S/C124S | − | − | − | 4.01±0.30 | 3.89±0.06 | 2.58±0.27 | nd | nd | nd |
| Sc eRF1 | CΔ19 | − | +/− − | + | 1.4±0.20 | 1.1±0.10 | 6.6±0.30 | YES | YES | YES |
¥
Symbols used to denote growth on YPD plates: (−) no growth; (+/− −) very weak growth; (+/−) weak growth; (+) modest growth; (++)moderate growth; (+++) good growth; (++++) optimal wild type growth as seen at 30°C. nd, not determined. nr, not recognized.
†
Readthrough values are represented as mean ± SD.