Demethylases
Demethylases are a group of enzymes that catalyze the removal of methyl groups (-CH3). Demethylation is a key mechanism in epigenetics, since the removal of a methyl group from histone proteins or DNA itself alters chromatin accessibility and subsequent gene expression. In addition to epigenetics, demethylation is also an integral process during bacterial chemotaxis, whereby demethylation of methyl-accepting chemotaxis proteins (MCPs) regulates the response of the bacterium to chemoattractants and repellents.