Fig. 3: MT1 and MT2 activation.
From: Structural basis of the ligand binding and signaling mechanism of melatonin receptors
a Structural comparison of the active (blue) and inactive (light blue) MT1. Three views are presented. b Comparison of the conformation of TM6 from MT1 with that from the Gi-coupled receptor μ-opioid (left, PDB ID: 6DDE) receptor and Gs-coupled receptor beta2 (right, PDB ID: 3SN6). c Structural comparison of active (green) and inactive (light green) MT2. Three views are presented. d Comparison of TM1 (left) and ICL2 (right) from MT1 and MT2. e–g Conformational changes of the key residues and motifs during receptor activation in MT1 (above) and MT2 (below). h The conformations of F6.41 in active (above) and inactive (below) MT1 and MT2 structures. i The Gi signaling ability of the F6.41 mutant of MT1 and MT2. Data were normalized to that of the wild-type receptor and presented as the means ± standard error of three replicates.
