Figure 1: Crystal structure variants of arrestin-1 and schematic of receptor binding equilibrium.
From: C-edge loops of arrestin function as a membrane anchor
(a) Structure of basal arrestin (PDB code 1CF1, molecule A)25. The N-domain is coloured blue, the C-domain is coloured green and the C-tail is orange. Important loops and regions referred to in this study are indicated. (b) Comparison of the β- and α-conformers of basal arrestin (1CF1)25, and the C-terminally truncated pre-active arrestin p44 (4J2Q)9. The interdomain rotation present in p44 is indicated by the rotation axis. (c) Unbound basal arrestin (grey) first interacts with the phosphorylated receptor C terminus in a low-affinity pre-complex. This initial interaction primes arrestin (orange) for the conformational transition required for full activation (red) and high-affinity coupling to the active receptor.
