Figure 2.

Functional characterization of SELEX-derived RNA pools. Binding to P protein was assessed by competition of the pool RNAs with radiolabelled wild-type Dε RNA (hatched bars); unlabelled wild-type Dε served as control. Complexes were immobilized to Ni²⁺-NTA agarose, washed, and the radioactivity remaining bound was measured by Cerenkov counting. The signal without competitor was set to 100%. Relative priming activities were determined by phosphoimaging of the priming signals (bottom panel) using the pool RNAs as template, and were normalized to the signal produced by the same concentration of wild-type Dε RNA set to 100% (grey shaded bars).