Structures and mechanisms of the RNA m A writer.

-methyladenosine (m A) is the most prevalent epigenetic modification found in eukaryotic mRNAs and plays a crucial role in regulating gene expression by influencing numerous aspects of mRNA metabolism. The m A writer for mRNAs and long non-coding RNAs consists of the catalytic subunit m A-METTL complex (MTC) (including METTL3/METTL14) and the regulatory subunit m A-METTL-associated complex (MACOM) (including HAKAI, WTAP, VIRMA, ZC3H13, and RBM15/15B). In this review, we focus on recent advances in our understanding of the structural and functional properties of m A writers and the possible mechanism by which they recognize RNA substrates and perform selective m A modifications.