Figure 3.
Aminoacylation status of newly synthesized tRNA. Cells were incubated at 37°C for either 10 min (lanes 1–8) or 1 h (lanes 9–12) before addition of [3H]uracil. Aminoacylated (lanes 1, 3, 5, 7, 9, and 11) and nonaminoacylated (lanes 2, 4, 6, 8, 10, and 12) tRNAs were isolated from W303 wild-type cells (lanes 1, 2, 9, and 10); SWY27, nup116Δ (lanes 3, 4, 11, and 12); NT33-5/YCpcca-M1, wild-type (lanes 5 and 6); and NT33-5/YCp50, cca1-1 (lanes 7 and 8; ref. 19) in the absence (lanes 1–8) or presence (lanes 9–12) of a 10-fold excess of nonaminoacylated yeast tRNA. RNAs were resolved on an acidic polyacrylamide gel and detected by fluorography.