Figure 3.

Characterization of individual round 9 aptamers. (A) Binding competition. ³⁵S-Met labelled P protein was incubated with 50 nM ³²P-labelled wild-type Dε RNA alone (lane wild-type), or plus the indicated aptamers at 2 μM concentration. Reaction products were separated by SDS-PAGE, and labelled protein and RNA were quantitated by phosphorimaging. The signal from the uncompeted reaction was set to 100%. (B) In vitro priming activities. In vitro transcribed aptamer RNAs were used as templates in priming assays. Reaction products were resolved by SDS-PAGE and ³²P-labelled P protein was visualized by phosphorimaging. Aptamer identities are given on the top; for s5 and s15, two plasmid DNAs derived from separate bacterial colonies were used (s5-1 and s5-2; s15-1 and s15-2) to confirm reproducibility. Relative priming signal intensities, with that from wild-type Dε set at 100%, are shown below the gel.