Self-splicing and protein-facilitated splicing of the 12 group I introns studied. (A) Results of the activity assays of the self-splicing introns (green). Introns that are inhibited upon CYT-18 binding are circled in red. (B) Results of the activity assays of the poorly self-splicing introns (cyan). (C) Results of the activity assays of the introns that are not self-splicing (dark blue). Intron abbreviations are defined in Table 1. Times of incubation are 1 h and 24 h. The numbers in the arrows indicate the total number of introns that followed each scenario. The previously uncharacterized circular product from the self-splicing reaction of the A.s. intron (indicated by an open circle) will be described elsewhere.
