S-adenosyl-L-methionine + adenine in DNA = S-adenosyl-L-homocysteine + N6-methyladenine in DNA
modification methylase; restriction-modification system
S-adenosyl-L-methionine:adenine in DNA N6-methyltransferase
This is a large group of enzymes, most of which form so-called ’restriction-modification systems’ with nucleases that possess similar site specificity [the nucleases are listed as either EC 184.108.40.206 (type 1 site-specific deoxyribonuclease), EC 220.127.116.11 (type II site-specific deoxyribonuclease) or EC 18.104.22.168 (type III site-specific deoxyribonuclease)]. A complete listing of all of these enzymes has been produced by R.J. Roberts and is available on-line at http://rebase.neb.com/rebase/rebase.html.