Fig. 2: Conformational changes of βarr1 upon binding to phosphorylated β₂V₂R in rHDLs bound to the full agonist.

a Structural differences of βarr1 between the basal state (gray, PDB ID: 1G4M) and in complex with β₁AR-V₂R_6P and Fab30 (purple, PDB ID: 6TKO). The structural model was prepared with Cuemol (http://www.cuemol.org/). b ¹H-¹³C HMQC spectra of [u-²H, Ileδ1-¹³C¹H₃] βarr1 in the basal state (left, black), the complex with phosphorylated β₂V₂R in rHDLs bound to the full agonist (middle, red), and the complex with both phosphorylated β₂V₂R in rHDLs bound to the full agonist and Fab30 (right, purple). c Normalized chemical shift differences between the basal state and the complex with phosphorylated β₂V₂R in rHDLs bound to the full agonist (left), and those between the complex with phosphorylated β₂V₂R in rHDLs bound to the full agonist and the complex with both phosphorylated β₂V₂R in rHDLs bound to the full agonist and Fab30 (right). Asterisks indicate residues with resonances broadened beyond detection upon the addition of phosphorylated β₂V₂R in rHDLs bound to the full agonist (left) and those upon the addition of Fab30 (right). N.D. indicates residues with resonances that were not observed both before (B; middle) and after (B; right) Fab30 addition. The error bars were calculated based on the digital resolution of the spectra, as described in “Methods”. d Distribution of the isoleucine residues on the structure of βarr1 in the basal state (PDB ID: 1G4M). The residues with resonances exhibiting chemical shifts larger than 0.1 ppm upon binding to phosphorylated β₂V₂R in rHDLs bound to the full agonist are shown as red spheres.