Figure 5.

Factors that promote group II intron splicing in Arabidopsis mitochondria. The diagram lists protein families and their members whose role in mitochondrial group II intron splicing has been inferred from analyses of loss-of-function mutants (see introduction for references) and indicates which introns depend on the function of a specific factor. Introns are named as in Figure 4; trans-spliced introns are indicated. Bold black introns are spliced exclusively via first-step hydrolysis, bold grey introns use both lariat and hydrolytic pathways, and all other introns are released as lariats. For nad1 intron 1, a hydrolytic pathway is assumed based on its secondary structure model (34).