Fig. 6: An alternative phospho-binding mode in the arrestin2-V2Rpp-4 complex.
From: Structural studies of phosphorylation-dependent interactions between the V2R receptor and arrestin-2
a pT359 bound at the V3′4′ site in the arrestin2 complex-V2Rpp-4 complex structure. Loss of pT360 in V2Rpp-4 altered the conformation of the phospho-segment ranging from P353 to T360, leading to the loss of the phospho-interaction at both the V4 site and V3 site and the transposition of pT359 to form hydrogen bond or charge-charge interactions with K11, K294, or R25 of arrestin2, respectively. This identified phospho-interaction site was designated the V3′4′ site. The orange balls indicate that the phosphorylated peptide remains bound to arrestin, the green balls indicate loss of the original interaction of the phospho-residue. The purple ball represents the found phospho-binding pocket of arrestin in the arrestin2-V2Rpp-4 complex structure. b Overall structural comparisons of arrestin2-V2Rpp-4 (orange) with the arrestin2-V2Rpp-FP complex (PDB: 4JQI, light cyan) and inactive arrestin2 (PDB:1G4M, gray). c V2Rpp-4 stabilized the clathrin binding region in arrestin by promoting hydrogen bond formation between Q189 and D194. d, e Structural rearrangement located in the MEK1 interaction region (d) and SRC interaction (P1) region (e) in the arrestin2-V2Rpp-4 complex.
