Figure 2.

The E.coli PAP I activity is not specific for ATP. (A) Synthetic transcribed [³²P]RNA of 380 nt was incubated with PAP I and 1 mM corresponding nucleotide. At 0, 5, 20, 40 and 60 min time points, the reaction was terminated and the RNA was isolated and analyzed by denaturing PAGE and autoradiography. (B) [³²P]RNA as in (A) was incubated with PAP I for 40 min without (–) or with ATP or GTP at the concentrations shown in the figure. Following incubation, the reaction was terminated and the RNA was isolated and analyzed by denaturing PAGE and autoradiography. (C) PAP I isolated from yeast was incubated with synthetic transcribed [³²P]RNA for 35 min without (–) or with the addition of 1 mM ATP, GTP, UTP or CTP. Following incubation, the RNA was isolated and analyzed as described in (A).