Recent developments in sequencing and bioinformatics have advanced our understanding of adenosine-to-inosine (A-to-I) RNA editing. Surprisingly, recent analyses have revealed the capability of adenosine deaminase acting on RNA (ADAR) to edit DNA:RNA hybrid strands. However, edited inosines in DNA remain largely unexplored. A precise biochemical method could help uncover these potentially rare DNA editing sites. We explore maleimide as a scaffold for inosine labeling. With fluorophore-conjugated maleimide, we were able to label inosine in RNA or DNA. Moreover, with biotin-conjugated maleimide, we purified RNA and DNA containing inosine. Our novel technique of inosine chemical labeling and affinity molecular purification offers substantial advantages and provides a versatile platform for further discovery of A-to-I editing sites in RNA and DNA.
Keywords: A‐to‐I RNA editing; adenosine deamination; chemical labeling; inosine; maleimide.
© 2024 The Authors. FEBS Letters published by John Wiley & Sons Ltd on behalf of Federation of European Biochemical Societies.