Helix formation in arrestin accompanies recognition of photoactivated rhodopsin.
Binding of arrestin to photoactivated phosphorylated rhodopsin terminates the amplification of visual signals in photoreceptor cells. Currently, there is no crystal structure of a rhodopsin-arrestin complex available, although structures of unbound rhodopsin and arrestin have been determined. High-affinity receptor binding is dependent on distinct arrestin sites responsible for recognition of rhodopsin activation and phosphorylation. The loop connecting beta-strands V and VI in rod arrestin has been implicated in the recognition of active rhodopsin. We report the structure of receptor-bound arrestin peptide Arr(67-77) mimicking this loop based on solution NMR data. The peptide binds photoactivated rhodopsin in the unphosphorylated and phosphorylated form with similar affinities and stabilizes the metarhodopsin II photointermediate. A largely alpha-helical conformation of the receptor-bound peptide is observed.
Feuerstein
Sophie E
SE
Department Strukturbiochemie (ISB-3), Institut für Strukturbiologie undBiophysik, Forschungszentrum Jülich, Germany.
Pulvermüller
Alexander
A
Hartmann
Rudolf
R
Granzin
Joachim
J
Stoldt
Matthias
M
Henklein
Peter
P
Ernst
Oliver P
OP
Heck
Martin
M
Willbold
Dieter
D
Koenig
Bernd W
BW
D019393:Arrestin / Q000737:chemistry*; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D010777:Photochemistry; D011487:Protein Conformation; D012243:Rhodopsin / Q000737:chemistry*
D019393:Arrestin; D012243:Rhodopsin