Fig. 2
ETB structure in complex with ET-3. a Comparison of the amino acid sequences of ET-1 and ET-3. b The overall structure of the ET-3-bound ETB receptor. The receptor is shown as an orange-red ribbon model. ET-3 is shown as a transparent surface representation and a ribbon model, with its N-terminal region coloured cyan, α-helical region orange, and C-terminal region deep pink. The side chains of ET-3 are shown as sticks. c, d Superimposition of the ET-3 and ET-1-bound ETB receptors, coloured orange-red and green, respectively, viewed from the membrane plane (c), and from the extracellular side (d). The side chains of ET-1 and ET-3 are shown as sticks. e, f Comparison of the interactions in the ET-1- (e) and ET-3- (f) bound structures. The receptors are shown as transparent surface representations and ribbon models. Endothelins are shown as ribbon models. The residues involved in the irreversible binding of the endothelins are shown as sticks
