ERβ Binds N-CoR in the Presence of Agonists. (A) Schematic of N-CoR primary structure. Silencing domains are indicated with hatched bars. NR binding regions (ID motifs) are illustrated with solid bars. (B) Radiolabeled ERβ retained by GST-N-CoR (amino acids 1944–2453) or GST-GRIP1 (amino acids 563–1121) after separation by SDS-PAGE. The amounts of bound proteins are compared to 10% of the input protein used in the binding assay in this experiment, and all results shown in the paper. (C) Radiolabeled ERβ retained by GST SMRT (amino acids 987–1491). (D) Radiolabeled ERα retained on GST-N-CoR beads in parallel. (E) Radiolabeled TRβ retained on GST-N-CoR and GST-GRIP1 beads in parallel.