S-adenosylmethionine, AdoMet or SAM is the major methyl donor for nucleic acids, proteins, lipids and small molecules in the reaction catalyzed by methyltransferases (MTs). Over 200 known and possible MTs have been identified, see PMID 20930037. Several DNA – check PMID 22332737, and protein methyltransferases are on this list – check PMIDs 23200123 and 22194015 for lysine MTs, PMIDs 21074527 and 23235912 for arginine MTs. Note the special case of Gnmt (first in the list), an abundant liver enzyme that may carry out a second and independent function in cellular detoxification; Gnmt can interact with 4S polycyclic aromatic hydrocarbons (PAH), which are potential carcinogens. The dimeric Gnmt is a PAH binder whereas the tetrameric form is required for the methyltransferase reaction. Genes are listed with aliases in parentheses, full names and links to gene report pages:
Gnmt – glycine N-methyltransferase
Dnmt1 (Mcmt, Cxxc9) – DNA methyltransferase 1
Dnmt3a (Dnmt3a2) – DNA methyltransferase 3 alpha
Dnmt3b (ICF) – DNA methyltransferase 3 beta
Suv39h1l1 (Kmt1a, histone-lysine N-methyltransferase 1a) – suppressor of variegation 3-9 homolog 1 (Drosophila)-like 1
Suv39h2 (Kmt1b, histone-lysine N-methyltransferase 1b) – suppressor of variegation 3-9 homolog 2
Ezh2 (Enx1, Kmt6) – enhancer of zeste 2 polycomb repressive complex 2 subunit
Smyd2 (HSKM-B, KMT3C) – SET and MYND domain containing 2
Dot1l (Kmt4, lysine N-methyltransferase 4) – DOT1 like histone lysine methyltransferase
Setd7 (Kmt7, lysine N-methyltransferase 7) – SET domain containing (lysine methyltransferase) 7
Kmt5a (Setd8, histone-lysine N-methyltransferase 5a) – lysine methyltransferase 5A
Prmt1 (Anm1) – protein arginine methyltransferase 1
Prmt2 – protein arginine methyltransferase 2
Prmt3 (Hrmt1l3) – protein arginine methyltransferase 3
Carm1 (Prmt4) – coactivator-associated arginine methyltransferase 1
Prmt5 (Jbp1, Skb1) – protein arginine methyltransferase 5
Prmt6 (Hrmt1l6) – protein arginine methyltransferase 6
Prmt7 – protein arginine methyltransferase 7
