Fig. 6. Poly(A)-site cleavage requires binding by CPF. (A) RNase H protection profile of purified CPF on sCYC1. The assays were performed with the same substrate and DNA oligonucleotides as described in the legend of Figure 4B. Protein-containing samples are indicated by CPF (lanes 9–16). For control, oligonucleotides were omitted in lanes 1 and 9. (B) RNase H protection assay as described above with purified CPF and mutant sCYC1-3GI+IV+V substrate. Only the region of the RNA substrate containing the mutated nucleotides is shown. Arrows indicate the poly(A)-site positions within sCYC1 and mutations are indicated as 3GII and 3GIV+V, respectively. Positions of sequences complementary to 14mer DNA oligonucleotides (3G-1 to 3G-4) are indicated.