Fig. 2.

In vitro methylation activity of FIONA1. a-c Representative LC-MS/MS chromatograms of d₃-m⁶A formed in RNA probes treated with or without FIONA1. The in vitro RNA N⁶-adenosine methylation activities of FIONA1 were tested using different RNA probes (numbered 1–6) containing sequence of UACAGAGAA, GGACC and UGUAU in a linear or looped structure in the presence of isotope-labeled cofactor d₃-SAM. d The peak area ratio of d₃-m⁶A versus one G in the probe (as internal control) was used to evaluate the methylation activities of FIONA1 towards different RNA oligos. Data are means ± SD for 2 biological replicates × 2 technical replicates