Potential transcriptional activator that may act by nicking the target promoter. Catalyzes the release of 5-methylcytosine (5-meC) from DNA by a glycosylase/lyase mechanism (By similarity). Binds 1 [4Fe-4S] cluster. The cluster does not appear to play a role in catalysis, but is probably involved in the proper positioning of the enzyme along the DNA strand. A number of isoforms are produced. According to EST sequences. The DEMETER domain, which is present in proteins of the subfamily, is related to the J-domain, but lacks some important conserved residues. Although strongly related to DNA glycosylase proteins, it differs from these proteins. The DNA repair function may not exist. Belongs to the DNA glycosylase family. DEMETER subfamily.