FIGURE 9.
A model for the reactions occurring during RNA splicing in Archaea. (A) Symmetric nature of the BHB-containing endonuclease substrate and two seven-base hairpin loops in ligase products. (B) Reactions involving specific phosphodiester linkages during RNA splicing. 1–9 and 1*–9* are residues involved in the formation of BHB in the substrates and hairpins in the products. Arrows in A indicate the splice sites in the substrate and products. The two phosphates (p1 and p2) and 2‘, 3′, and 5′ positions involved in the reactions are indicated. (E1 and E2) Two exons; (I) intron.
