FIGURE 4.
(A) Splicing schema of the human SF1 gene (Splicing Factor 1). Cylinders denote exons, which are enumerated in the 5′-to-3′ direction; filled circles denote boxes; dotted arcs denote complementarity between boxes; solid lines denote splicing; the arrow denotes an alternative transcription start. Box C is complementary to box F (P-value ≅ 10−17), which is also complementary to box E (P-value ≅ 10−19). Box G is complementary to both box H (P-value ≅ 10−12) and box I (P-value ≅ 10−14). (B–E) Multiple sequence alignments describing box E-box F pairing (B), box C-box F pairing (C), box G-box I pairing (D), and box G-box H pairing (E). Complementary nucleotides are highlighted. Framed capital nucleotides denote exons. Asterisks denote conserved positions.