A dimeric viral SET domain methyltransferase specific to Lys27 of histone H3.Manzur, K.L., Farooq, A., Zeng, L., Plotnikova, O., Koch, A.W., Sachchidanand, Zhou, M.-M.
(2003) Nat Struct Biol 10: 187-196
- PubMed: 12567185
- DOI: https://doi.org/10.1038/nsb898
- Primary Citation of Related Structures:
- PubMed Abstract:
Site-specific lysine methylation of histones by SET domains is a hallmark for epigenetic control of gene transcription in eukaryotic organisms. Here we report that a SET domain protein from Paramecium bursaria chlorella virus can specifically di-methylate Lys27 in histone H3, a modification implicated in gene silencing. The solution structure of the viral SET domain reveals a butterfly-shaped head-to-head symmetric dimer different from other known protein methyltransferases. Each subunit consists of a Greek-key antiparallel beta-barrel and a three-stranded open-faced sandwich that mediates the dimer interface. Cofactor S-adenosyl-L-methionine (SAM) binds at the opening of the beta-barrel, and amino acids C-terminal to Lys27 in H3 and in the flexible C-terminal tail of the enzyme confer the specificity of this viral histone methyltransferase.
Structural Biology Program, Department of Physiology and Biophysics, Mount Sinai School of Medicine, New York University, One Gustave L. Levy Place, New York, New York 10029, USA.