[HTML][HTML] Histone methyltransferase activity of a Drosophila Polycomb group repressor complex
Cell, 2002•cell.com
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 …
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 …
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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