Structures of human PRC2 with its cofactors AEBP2 and JARID2

Complete architecture of PRC2 Polycomb repressive complex 2 (PRC2) methylates lysine 27 in histone H3 to achieve gene silencing. Kasinath et al. report multiple structures of complete human PRC2 with its four core subunits (EZH2, EED, SUZ12, and RBAP48) and two cofactors (AEBP2 and JARID2) in different active states. These structures describe the molecular mimicry of H3 tails by AEBP2 and JARID2 to regulate PRC2 activity and reveal the organizational role of SUZ12 in maintaining the integrity and stability of the complex. Science , this issue p. 940