The WD40 domain-containing protein EED is the regulatory subunit of Polycomb repressive complex 2 (PRC2) [, ], which mediates gene silencing primarily through methylation of lysine-27 of histone H3 []. The core subunits of the complex in mammals include EED, EZH2, SUZ12 and RBBP4. PRC2 is well conserved throughout evolution. In Drosophila the core subunits of the complex include ESC, E(Z), CAF1 (NURF-55) and SU(Z)12 [, ]. Drosophila has two copies of the Eed homologue, Esc and Esc-like [].
This family of proteins is found in bacteria and archaea. Proteins in this family are typically between 247 and 291 amino acids in length. There is a conserved EED sequence motif. This is a putative metallopeptidase.
This domain can be found in the polycomb repressive complex 2 (PRC2) subunits EZH1 and EZH2. Three core subunits make up the catalytic core of PRC2: EZH1 or EZH2, the zinc-finger containing SUZ12 and EED. Polycomb complexes maintain repressive chromatin states by silencing gene expression. PRC2 does this by methylating lysine 27 of histone H3 []. This domain makes up part of the N-lobe which consists of EED and the N-terminal region of EZH2, and is involved in regulation [].
This entry represents the coiled-coil region of Huntingtin-interacting protein 1 (HIP1). It carries a highly conserved HADLLRKN sequence motif at its N terminus which effects the binding of HIP1R to clathrin light-chain EED regulatory site. This binding then stimulates clathrin lattice assembly. HIP1 is an obligate binding partner for Huntingtin, and loss of this interaction triggers the cascade of events that results in the apoptosis of neuronal cells and the onset of Huntington's disease []. Clathrin light-chain binds to a flexible coiled-coil domain in HIP1 and induces a compact state that is refractory to actin binding [].
