FIGURE 2.

Splicing catalysis, the spliceosome assembly pathway, and mechanisms of splice site selection. A, Diagram of an intron, 2 flanking exons, U1 and U2 snRNP, associated RNA binding proteins, and U2 snRNA, and the sequential reactions involved in removal of an intron. The U2 snRNP complex and U2AF complex recognize the BPS and 3′ss, respectively, which is an essential step for removing introns from pre‐mRNA. Accessory splicing regulatory proteins are also involved in splicing. B, Classification of alternative RNA splicing