PMID: 12389038 , Related PDB ids: 1MT6, 1MUF
Jacobs SA, Harp JM, Devarakonda S, Kim Y, Rastinejad F, Khorasanizadeh S
The active site of the SET domain is constructed on a knot.
Nat Struct Biol. 2002 Nov;9(11):833-8.
The SET domain contains the catalytic center of lysine methyltransferases that target the N-terminal tails of histones and regulate chromatin function. Here we report the structure of the SET7/9 protein in the absence and presence of its cofactor product, S-adenosyl-L-homocysteine (AdoHcy). A knot within the SET domain helps form the methyltransferase active site, where AdoHcy binds and lysine methylation is likely to occur. A structure-guided comparison of sequences within the SET protein family suggests that the knot substructure and active site environment are conserved features of the SET domain.