Analysis of high-affinity RNA 1/(MS2)2. (A) Sequences within the randomized region of RNA 1/(MS2)2 were individually deleted to obtain hybrid RNAs 1a–g/(MS2)2. (B, left) Growth assay for HIS3 expression on selective medium containing a gradient of 0–35 mM 3-AT. (Right) Colony filter-lift assay for LacZ reporter gene expression. Two independent transformants of each strain are shown. (C) Predicted secondary structures of hybrid RNAs 1d/(MS2)2 and 1e/ (MS2)2. MS2 recognition sequences are shown in gray, and unique sequences are highlighted in red. (D) RNAs 1/(MS2)2 and 1d/(MS2)2 accumulate to the same level. Yeast total RNA was extracted and assayed by Northern blotting, probing with radiolabeled oligonucleotides complementary to the RNase P RPR1 leader and to the U6 snRNA. Mobilities of DNA size markers are indicated.
