histone-lysine N-methyltransferase SUV39H2; histone H3-K9 methyltransferase 2; H3-K9-HMTase 2; lysine N-methyltransferase 1B; suppressor of variegation 3-9 homolog 2; Su(var)3-9 homolog 2 (SUV39H2, KMT1B)

Function: - histone methyltransferase - specifically trimethylates Lys-9 of histone H3 using monomethylated H3 Lys-9 as substrate - H3 Lys-9 trimethylation represents a specific tag for epigenetic transcriptional repression by recruiting HP1 (CBX1, CBX3 &/or CBX5) proteins to methylated histones - mainly functions in heterochromatin regions, thus playing a role in the establishment of constitutive heterochromatin at pericentric & telomere regions - H3 Lys-9 trimethylation is also required to direct DNA methylation at pericentric repeats - targeted to histone H3 via its interaction with RB1 - SUV39H1 is involved in many processes, such as a) cell cycle regulation b) transcriptional repression c) regulation of telomere length - may participate in regulation of higher order chromatin organization during spermatogenesis - interacts with SMAD5 S-adenosyl-L-methionine + L-lysine-[histone] = S-adenosyl-L-homocysteine + N(6)-methyl-L-lysine-[histone] Structure: - although the SET domain contains the active site, both pre-SET & post-SET domains are required for methyltransferase activity - the SET domain also participates in stable binding to heterochromatin (putative) - belongs to the histone-lysine methyltransferase family, Suvar3-9 subfamily - contains 1 chromo domain - contains 1 post-SET domain - contains 1 pre-SET domain - contains 1 SET domain Compartment: - nucleus, chromosome, centromere - associates with centromeric constitutive heterochromatin (putative) Alternative splicing: named isoforms=3

General

histone N-methyltransferase phosphoprotein

Properties

SIZE: entity length = 410 aa MW = 47 kD COMPARTMENT: cell nucleus MOTIF: acetylation site SITE: N-TERMINUS EFFECTOR-BOUND: acetyl chromodomain NAME: chromodomain SITE: 47-105 FOR-BINDING-OF: heterochromatin pre-SET domain {189-247} SET domain {249-377} Ser phosphorylation site {S381} Ser phosphorylation site {S382} Ser phosphorylation site {S384} Ser phosphorylation site {S388} post-SET domain {394-410}

Database Correlations

OMIM 606503 UniProt Q9H5I1 PFAM correlations Entrez Gene 79723 Kegg hsa:79723 ENZYME 2.1.1.43

References

UniProt :accession Q9H5I1