Fig. 2
From: Intermediate introns in nuclear genes of euglenids – are they a distinct type?
Homologous introns at position 9 in tubB genes. A comparison of RNA secondary structure of introns at position 9 in tubB genes from six strains of E. agilis. The middle part of the sequence is omitted and indicated by dots. Exons in black circles, introns in gray; nucleotides present in all six sequences highlighted in red, in five of six in orange, in four of six in yellow. Classical Watson-Crick base-pairing interactions are marked by single (AU) or double (GC) lines, non-canonical GU pairs by single line with circle. Note: the U/A base pair is present at positions +5/-7 instead of A/U observed in other nonconventional introns