InterPro domain: IPR025800

Methyltransferases (EC [intenz:2.1.1.-]) constitute an important class of enzymes present in every life form. They transfer a methyl group most frequently from S-adenosyl L-methionine (SAM or AdoMet) to a nucleophilic acceptor such as oxygen leading to S-adenosyl-L-homocysteine (AdoHcy) and a methylated molecule [ 1 , 2 , 3 ]. All these enzymes have in common a conserved region of about 130 amino acid residues that allow them to bind SAM [ 4 ]. The substrates that are methylated by these enzymes cover virtually every kind of biomolecules ranging from small molecules, to lipids, proteins and nucleic acids [ 5 , 5 , 5 ]. Methyltransferase are therefore involved in many essential cellular processes including biosynthesis, signal transduction, protein repair, chromatin regulation and gene silencing [ 5 , 5 , 5 ]. More than 230 families of methyltransferases have been described so far, of which more than 220 use SAM as the methyl donor.

Members of this family are calmodulin-lysine N-methyltransferase ( 2.1.1.60 ) that catalyse the trimethylation of 'Lys-116' in calmodulin [ 5 ]. The enzyme is cytosolic and is found at high levels in tissues with high levels of calmodulin [ 6 ].

1. Natural history of S-adenosylmethionine-binding proteins. BMC Struct. Biol. 5, 19
2. Comprehensive structural and substrate specificity classification of the Saccharomyces cerevisiae methyltransferome. PLoS ONE 6, e23168
3. Many paths to methyltransfer: a chronicle of convergence. Trends Biochem. Sci. 28, 329-35
4. Universal catalytic domain structure of AdoMet-dependent methyltransferases. J. Mol. Biol. 247, 16-20
5. Calmodulin methyltransferase is an evolutionarily conserved enzyme that trimethylates Lys-115 in calmodulin. Nat Commun 1, 43
6. Calmodulin N-methyltransferase. Partial purification and characterization. J. Biol. Chem. 261, 7060-9