FIGURE 7.

Ribozyme activity assays. (A) The fraction of RNA that self-cleaves after incubation under the same conditions used during in vitro evolution for families 1, 2, 4, 7, 9, and 13 in absence (hashed bars) or presence (solid bars) of montmorillonite. Data are represented as mean ± SE. (B–D) Time courses of self-cleavage activity for families 1,2, and 4 in the absence (open symbols) or presence (filled symbols) of montmorillonite. For time courses, cleavage at t₀ was subtracted and data were normalized to the extent of cleavage at 180 min in the [−]clay conditions. The data are fit with single or double exponential curves (solid lines). Rate constants and amplitudes are indicated in the graphs.