FIGURE 1.
Sequence alignment of the canonical U1 snRNA with the vU1 snRNAs. Conserved bases are indicated with a dot and alterations are shown with base symbols. A dash indicates the absence of a base at that position. The 5′-region that base pairs with splice sites, stem–loops, and the Sm site of U1 snRNA are boxed and indicated below the aligned sequences. Nucleotides that have been reported to be involved in interactions of SL1 with U1-70K (Kondo et al. 2015; Gopan et al. 2022), SL2 with U1A (Kormos et al. 2011), and SL4 with SF3A1 (de Vries et al. 2022; Nameki et al. 2023) are underlined.
