Denaturing gel showing biotinylated RNA product sizes after in vitro transcription.

Biotinylated RNA was run on urea polyacrylamide gels (7% top; 5% bottom) after heating the RNA (0.5 μg) samples. Sample are as indicated (see Fig 3 for a diagram of the region that was transcribed). Wild-type (wt) was the originally cloned sequence, and the mutations (mut) introduced to each region and all combinations are as shown in Fig 3.

(TIF)