InterPro domain: IPR001091

Site-specific DNA-methyltransferase, N-6 adenine-specific DNA methylase ( 2.1.1.72 ) and cytosine-N4-specific ( 2.1.1.113 ) are enzymes thatspecifically methylate the amino group at the C-4 position of cytosines and the N-6 position of adenine inDNA. In prokaryotes, the major role of DNA methylation is to protect hostDNA against degradation by restriction enzymes. There are two major classesof DNA methyltransferase that differ in the nature of the modificationsthey effect. The members of one class (C-MTases) methylate a ring carbon andform C5-methylcytosine and members of the second class (N-MTases) methylateexocyclic nitrogens and form either N4-methylcytosine (N4-MTases) orN6-methyladenine (N6-MTases). Both classes of MTase utilise the cofactorS-adenosyl-L-methionine (SAM) as the methyl donor and are active as monomeric enzymes[ 1 ].

1. Structure and function of DNA methyltransferases. null 24, 293-318