Fig. 3: Unique interface between KOR and Nb6.
From: Nanobody-enabled monitoring of kappa opioid receptor states
a Details of the interface between KOR (green) and Nb6 (purple) are shown. b Mutagenesis studies using BRET identify key residues essential for KOR–Nb6 interactions. Error bars represent SEM. (N = 3) c left, ionic-lock in β2AR stabilizing the S2 inactive state; middle, R3.50 forms two hydrogen bonds with T2.39 and T6.34, respectively. These interactions mimic the ionic lock observed in β2AR; right, R102 in Nb6 mediates a new H-bond network between TM5 and TM6. This interaction is not observed in either KOR–JDTic inactive or KOR–Nb39 active states. Source data are provided as a Source Data file.
