Table 2. Reverse cyclization products.

(A) Reverse cyclization products (written 5′→3′) of the combinatorial assay at 15 mM MgCl₂ (24 total). The dashed lines represent a single phosphodiester bond. The solid lines represent nucleobase continuation within the intron. The numbering system for exon substrate positions is indicated above the sequences. Note that position –1 is RNA and was not randomized, while positions –2 through to –6 are DNA and were randomized. (B) Sequence of the IGS of the rP-h intron (and the rP-8/4x ribozyme). (C) The percent occurrence of each nucleobase at each exon position.