B. stearothermophilus trp leader RNA structure formation in the absence and presence of a competing oligonucleotide. 5′ 32P-labeled trp leader RNA (1–191) was subjected to partial RNase T1 digestion without or with a DNA oligonucleotide complementary to nt 36–61. Samples in lanes 1–3 were renatured in the absence of the competing oligonucleotide; samples in lanes 4–6 were renatured in the presence of 10 μM oligonucleotide. C, OH−, and T1 are as in Figure 5. Important secondary structural features are given on the left side of the gel, including the triplet repeat number. Arrowheads indicate sites of increased cleavage in the presence of competing oligonucleotide and TK100M4. Numbering at the right is from the start of transcription.
