X-Ray Crystal Structure of the Ancestral 3-Ketosteroid Receptor–Progesterone–Mifepristone Complex Shows Mifepristone Bound at the Coactivator Binding Interface

X-Ray Crystal Structure of the Ancestral 3-Ketosteroid Receptor–Progesterone–Mifepristone Complex Shows Mifepristone Bound at the Coactivator Binding Interface