Structural rearrangements at the domain interface in the ELIC-GLIC chimera. (A) Overlays of Apo-ELIC (PDB accession no. 3RQU) and ELIC-GABA-flurazepam (PDB accession no. 4A96) (left) and spin-normalized CW spectra of interface domain residues L29R1 (β1–β2 loop), V82R1 (β4–β5 loop), M114R1, and F116R1 (β6–β7 loop) in the apo state, in the presence of 20 mM 3-AP, or at pH 3.0 (right). (B) Overlay of GLIC structures in the closed (PDB accession no. 4NPQ) and open conformations (PDB accession no. 4HFI; left). CW-EPR spectra of K255R1 (M2–M3 linker) and F322R1 (M4) in the apo state, in the presence of 20 mM 3-AP, and at pH 3.0 (right).