Reaction: 2 S-adenosyl-L-methionine + a [histone H3]-L-lysine9 = 2 S-adenosyl-L-homocysteine + a [histone H3]-N6,N6-dimethyl-L-lysine9 (overall reaction)
(1a) S-adenosyl-L-methionine + a [histone H3]-L-lysine9 = S-adenosyl-L-homocysteine + a [histone H3]-N6-methyl-L-lysine9
(1b) S-adenosyl-L-methionine + a [histone H3]-N6-methyl-L-lysine9 = S-adenosyl-L-homocysteine + a [histone H3]-N6,N6-dimethyl-L-lysine9
Other name(s): SUVH1 (gene name); SUVR1 (gene name); SET32 (gene name); SDG32 (gene name); SET13 (gene name)
Systematic name: S-adenosyl-L-methionine:[histone H3]-L-lysine9 N6-dimethyltransferase
Comments: This entry describes several enzymes, characterized from plants, that successively methylate the L-lysine-9 residue of histone H3 (H3K9) twice, ultimately generating a dimethylated form. These modifications influence the binding of chromatin-associated proteins. In general, the methylation of H3K9 leads to transcriptional repression of the affected target genes. cf. EC 2.1.1.367, [histone H3]-lysine9 N-methyltransferase, EC 2.1.1.366, [histone H3]-N6,N6-dimethyl-lysine9 N-methyltransferase, and EC 2.1.1.355, [histone H3]-lysine9 N-trimethyltransferase.
Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc CAS registry number:
References:
1. Yu, Y., Dong, A. and Shen, W.H. Molecular characterization of the tobacco SET domain protein NtSET1 unravels its role in histone methylation, chromatin binding, and segregation. Plant J. 40 (2004) 699-711. [PMID: 15546353]
2. Shen, W.H. and Meyer, D. Ectopic expression of the NtSET1 histone methyltransferase inhibits cell expansion, and affects cell division and differentiation in tobacco plants. Plant Cell Physiol. 45 (2004) 1715-1719. [PMID: 15574848]
3. Naumann, K., Fischer, A., Hofmann, I., Krauss, V., Phalke, S., Irmler, K., Hause, G., Aurich, A.C., Dorn, R., Jenuwein, T. and Reuter, G. Pivotal role of AtSUVH2 in heterochromatic histone methylation and gene silencing in Arabidopsis. EMBO J. 24 (2005) 1418-1429. [PMID: 15775980]