Fig. 4.

Secondary structure of group II intron UHB.I2. UHB.I2 identified in TSL2 contig shows necessary sequences required for intron splicing and reverse splicing. Important sequences are shown within red rectangles or curved lines. EBS1 and EBS3 are important for base-pairing with target site in flanking exons, whereas other identified sequences are necessary for intron folding (Watson-Crick α-α’, β-β’, Ɛ-Ɛ’and γ-γ’ and non-Watson-Crick ĸ-ĸ’ and λ-λ’ internal base-pairing and tetraloop-receptor interactions ζ-ζ’ and η-η’). Conserved catalytic “AGC” triad in DV is shown in a green rectangle