Fig. 1.

The primary type and mechanism of DNA methylation. DNA methylation typically occurs as 5mC, with DNMT1 being the key methyltransferase (writer) and the TET family proteins playing the primary demethylation (eraser) role. Three kinds of DNA methylation-binding proteins (reader) were reported, which are MBD (Methyl-CpG-Binding Domain), Kaiso and SRA (Set and Ring Finger-associated) families. Readers identify methylated DNA sites to enable the downstream effects including, for example, gene expression suppression and genomic methylation maintenance.