IUBMB Enzyme Nomenclature


Accepted name: [histone H3]-lysine4 N-trimethyltransferase

Reaction: 3 S-adenosyl-L-methionine + a [histone H3]-L-lysine4 = 3 S-adenosyl-L-homocysteine + a [histone H3]-N6,N6,N6-trimethyl-L-lysine4 (overall reaction)
(1a) S-adenosyl-L-methionine + a [histone H3]-L-lysine4 = S-adenosyl-L-homocysteine + a [histone H3]-N6-methyl-L-lysine4
(1b) S-adenosyl-L-methionine + a [histone H3]-N6-methyl-L-lysine4 = S-adenosyl-L-homocysteine + a [histone H3]-N6,N6-dimethyl-L-lysine4
(1c) S-adenosyl-L-methionine + a [histone H3]-N6,N6-dimethyl-L-lysine4 = S-adenosyl-L-homocysteine + a [histone H3]-N6,N6,N6-trimethyl-L-lysine4

Other name(s): KMT2H (gene name); KMT3C (gene name); KMT3D (gene name); KMT3E (gene name); PRDM9 (gene name); MLL5 (gene name); ASH1L (gene name); SMYD1 (gene name); SMYD2 (gene name); SMYD3 (gene name)

Systematic name: S-adenosyl-L-methionine:[histone H3]-L-lysine4 N6-trimethyltransferase

Comments: This entry describes several enzymes that successively methylate the L-lysine4 residue of histone H3 (H3K4), ultimately generating a trimethylated form. These modifications influence the binding of chromatin-associated proteins. In most cases the trimethylation of this position is associated with gene activation. EC,, [histone H3]-lysine4 N-methyltransferase, describes enzymes that can catalyse only monomethylation of this substrate (the first sub-reaction of this entry); EC, [histone H3]-lysine4 N-dimethyltransferase, describes enzymes that catalyse only dimethylation of this substrate (the first two sub-reactions of this entry)

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number:


1. Nakamura, T., Mori, T., Tada, S., Krajewski, W., Rozovskaia, T., Wassell, R., Dubois, G., Mazo, A., Croce, C.M. and Canaani, E. ALL-1 is a histone methyltransferase that assembles a supercomplex of proteins involved in transcriptional regulation. Mol. Cell 10 (2002) 1119-1128. [PMID: 12453419]

2. Hamamoto, R., Furukawa, Y., Morita, M., Iimura, Y., Silva, F.P., Li, M., Yagyu, R. and Nakamura, Y. SMYD3 encodes a histone methyltransferase involved in the proliferation of cancer cells. Nat. Cell Biol. 6 (2004) 731-740. [PMID: 15235609]

3. Blazer, L.L., Lima-Fernandes, E., Gibson, E., Eram, M.S., Loppnau, P., Arrowsmith, C.H., Schapira, M. and Vedadi, M. PR domain-containing protein 7 (PRDM7) is a histone 3 lysine 4 trimethyltransferase. J. Biol. Chem. 291 (2016) 13509-13519. [PMID: 27129774]

[EC created 1976 as EC, modified 1982, modified 1983, part transferred 2019 to EC, modified 2020]

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