Figure 4.

Limited effects on splicing of atomic or abasic mutations of U6 nucleotides in the triple helix structure. (A–D) Quantification of the kinetics of mRNA and intermediate production after performing splicing with indicated synthetic U6 snRNA mutants. The corresponding splicing assays are shown in Supplementary Figure S2 and quantification was as in Figure 3. The mutants in panels A-D were all analysed in one experimental series to ensure that the quantification relative to the wt U6 was reliable. The average amount of mRNA or intron lariat-3′ exon (denoted as intermediate) present (plus the standard error) at each time point was calculated from three independent experiments, with the exception of panel D which was derived from two independent experiments.