Fig. 5.

Newly-synthesized RNA labeled with [α-³²P]GTP or [α-³²P]ATP was prepared in permeabilized cells, the spliced leader RNA was gel purified and analyzed by tobacco acid pyrophosphatase and P1 digestion. In both panels, the SL RNA was isolated from uninduced cells (lane 1), or from cells depleted for TbCGM1 for 1 day (lane 2) or 2.5 days (lane 3). (A) The cap nucleotide was visualized by digesting [α-³²P]GTP-labeled SL RNA with tobacco acid pyrophosphatase and TLC separation. The positions of nonradioactive m⁷Gp and Gp markers (visualized with UV light) are indicated. (B) [α-³²P]ATP-labeled SL RNA was treated with nuclease P1 and separated by TLC. Two different exposure times are shown. The positions of nonradioactive AMP, ADP and ATP markers (visualized with UV light) are indicated.