Figure 4. Extended Data Figure 4.

Representative gel images of RNA-catalysed alkylation reactions of RNA substrate mutants by their corresponding ribozymes with complementary binding arms as listed in Supplementary Table 1. a. adenosine point mutations. b. atomic mutagenesis of backbone. c, d. atomic mutagenesis of adenosine. e. reactions sites blocked by methylation. f. binding arm mutations outside of GAG. g. point mutations next to target nucleoside A. Reactions were performed with 100 μM BG-NH₂ (a - e) or SNAP-biotin (f - g) at pH 7.5, 40 mM MgCl₂, 37°C and repeated two times for each substrate. The parent reaction with adenosine was performed with fluorescently labelled and radioactively labelled RNA independently for six times.