The n-SET or N-SET domain is a component of the COMPASS complex, associated with SET1, conserved in yeasts and in other eukaryotes up to humans. The COMPASS complex functions to methylate the fourth lysine of Histone 3 and for the silencing of genes close to the telomeres of chromosomes [2]. This domain promotes trimethylation in conjunction with an RRM domain [4] and is necessary for binding of the Spp1 component of COMPASS into the complex [3].

1: The Saccharomyces cerevisiae Set1 complex includes an Ash2 homologue and methylates histone 3 lysine 4. Roguev A, Schaft D, Shevchenko A, Pijnappel WW, Wilm M, Aasland R, Stewart AF; EMBO J 2001;20:7137-7148. PMID:11742990

2: COMPASS, a histone H3 (Lysine 4) methyltransferase required for telomeric silencing of gene expression. Krogan NJ, Dover J, Khorrami S, Greenblatt JF, Schneider J, Johnston M, Shilatifard A; J Biol Chem. 2002;277:10753-10755. PMID:11805083

3: Protein interactions within the Set1 complex and their roles in the regulation of histone 3 lysine 4 methylation. Dehe PM, Dichtl B, Schaft D, Roguev A, Pamblanco M, Lebrun R, Rodriguez-Gil A, Mkandawire M, Landsberg K, Shevchenko A, Shevchenko A, Rosaleny LE, Tordera V, Chavez S, Stewart AF, Geli V; J Biol Chem. 2006;281:35404-35412. PMID:16921172

4: Histone trimethylation by Set1 is coordinated by the RRM, autoinhibitory, and catalytic domains. Schlichter A, Cairns BR; EMBO J. 2005;24:1222-1231. PMID:15775977