5-Methylcytosine

5-Methylcytosine is a methylated nucleotide base found in eukaryotic DNA. In animals the DNA methylation of cytosine to form 5-methylcytosine is found primarily in the palindromic sequence CpG. In plants the methylated sequence is CpNpGp where N can be any base. 5-Methylcytosine is an epigenetic modification formed by the action of DNA methyltransferases. In bacteria 5-methylcytosine can be found at a variety of sites and is often used as a marker to protect DNA from being cut by native methylation-sensitive restriction enzymes.