The enzymes responsible for the removal of methyl groups from histone are histone demethylases .
The enzymes responsible for the addition of methyl groups to histones are called histone methyltransferases ( HMTs ) .
The enzymes responsible for the removal of methyl groups from histone are enzymes   .
The enzymes responsible for the addition of methyl groups to histones are called histone methyltransferases ( HMTs ) .