FIGURE 5.

A248 mutant cleavage specificity as a function of substrate base composition. (A) Fraction correct cleavage by native and A248 mutant ribozymes for substrates that were varied at N(-1). The fraction correct cleavage of dA(-1) is shown with white bars; dG(-1) with black bars; dC(-1) with gray bars; and dU(-1) with cross-hatched bars. Error bars indicate the standard deviation of three or more independent measurements. (B) Miscleavage as a function of N(-2) base identity, for substrates with dA at N(-1). White bars indicate the fraction of miscleavage for A(-2), black bars G(-2), gray bars C(-2), and cross-hatched bars U(-2).