Table 1.
The dependency of decapping on mRNA/cap/product binding
| Competitor | Decapped (%) | SEM (+/−) |
|---|---|---|
| Panel A | ||
| None | 68.4 | 0.7 |
| Uncapped Omp mRNA(164 μM) | 37.8 | 2.1 |
| 7-methyl diguanosine triphosphate (164 μM) | 69 | 1 |
| Panel B | ||
| None | 44.3 | 0.3 |
| 7-methyl GDP (2 mM) | 25.3 | 1.4 |
| 7-methyl GDP (0.2 mM) | 29.4 | 0.1 |
(A) The extent of decapping of the substrate was measured after 60 min in assays containing GST-AtDcp2-PD-His10 protein, 5 mM Mn2− and a fixed amount (0.14 nM) of radiolabelled capped Omp mRNA, supplemented with 164 μM each of the competitors: uncapped Omp and cap analog dinucleotide. The SEM of three separate assays for each competitor are also indicated. All other conditions are as described in the ‘Materials and methods’ section. (B) The extent of decapping of the substrate by the recombinant enzyme in the presence and absence of the reaction product 7-methyl GDP after 60 min.