Assays were carried out in reaction mixture [40 mM Tris-HCl (pH 8.0), 1 mM DTT, 1 mM MgCl2, 2 μM SAM and 0.1 μM 3H-SAM] in the presence of 0.7 μM GpppAC4 synthetic RNA and incubated at 30 °C.