Figure1. DNA methylation
In the catalysis of DNA methyltransferases (DNMT1, DNMT3a and DNMT3b), a
methyl (CH3) group is added into a cytosine base, which
occurs mainly in CpGs. DNA methylation require the transfer of a methyl
group from SAM resulting in the formation of SAH, which is then cleaved
into adenosine and homocysteine.