Article

Histone methyltransferase activity of a Drosophila Polycomb group repressor complex.

EMBL, Gene Expression Programme, Meyerhofstr. 1, 69117 Heidelberg, Germany.
Cell (impact factor: 32.4). 11/2002; 111(2):197-208.
Source: PubMed

ABSTRACT Polycomb group (PcG) proteins maintain transcriptional repression during development, likely by creating repressive chromatin states. The Extra Sex Combs (ESC) and Enhancer of Zeste [E(Z)] proteins are partners in an essential PcG complex, but its full composition and biochemical activities are not known. A SET domain in E(Z) suggests this complex might methylate histones. We purified an ESC-E(Z) complex from Drosophila embryos and found four major subunits: ESC, E(Z), NURF-55, and the PcG repressor, SU(Z)12. A recombinant complex reconstituted from these four subunits methylates lysine-27 of histone H3. Mutations in the E(Z) SET domain disrupt methyltransferase activity in vitro and HOX gene repression in vivo. These results identify E(Z) as a PcG protein with enzymatic activity and implicate histone methylation in PcG-mediated silencing.

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Keywords

Drosophila embryos
 
enzymatic activity
 
essential PcG complex
 
Extra Sex Combs
 
four subunits methylates lysine-27
 
full composition
 
histone H3
 
major subunits
 
methyltransferase activity
 
PcG repressor
 
Polycomb group
 
recombinant complex reconstituted
 
SET domain
 
transcriptional repression
 
vitro
 
Zeste [E(Z)] proteins