Fig. 1. C–H oxidation by TET enzymes. (A) Schematic showing active DNA demethylation via TET-mediated successive C–H oxidation of 5mC to 5hmC, 5fC and 5caC followed by TDG catalyzed base hydrolysis and repair. (B) Structures of the 5-alkylcytosine derivatives synthesized and examined for TET activity. DNMT: DNA methyltransferase, SAM: S-adenosylmethionine.
