Nucleotide composition by position

It has been determined that certain internal RNA editing events occur in miRNAs. For instance, ADAR enzymes catalyze the A-to-I conversion (Wang and Liang, 2018), thus altering miRNA targeting in tumors (Paul et al., 2017; Roberts et al., 2018). In NGS results, inosine is read as the misincorporation of a G, while m1A methylation is read as the misincorporation of random nucleotides with a concurrent drop in the sequence coverage (Schwartz and Motorin, 2017). In order to identify such editing events, as well as other templated and non-templated incorporations on the 5’ and 3’ ends, the section “Nucleotide composition by position” reports the percentage of each nucleotide found in each position in all the aligned isomiRs.