Two reactions of Haloferax volcanii RNA splicing enzymes: Joining of exons and circularization of introns

Sequences of pre-tRNA^Trp (A), elongator pre-tRNA^Met (D), and their spliced products: ligated exons (B and E) and circularized introns (C and F). Arrowheads in A and D denote the splice sites within the bulge-helix-bulge (BHB) motifs. Anticodons are highlighted. Asterisks in B, C, E, and F denote the splice junctions. Positions corresponding to the oligonucleotides used for RT-PCR (Figs. 2B, 3A) and Northern hybridizations (Fig. 4) are labeled and marked by the lines ending in half arrows. Bases within parentheses in C indicate the changes in various synthetic intron-like transcripts (Fig. 8).