title: Helix formation in arrestin accompanies recognition of photoactivated rhodopsin.
abstract: 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.
authors.affiliation: Department Strukturbiochemie (ISB-3), Institut für Strukturbiologie undBiophysik, Forschungszentrum Jülich, Germany.
authors.forename: Sophie E
authors.initials: SE
authors.lastname: Feuerstein
authors.forename: Alexander
authors.initials: A
authors.lastname: Pulvermüller
authors.forename: Rudolf
authors.initials: R
authors.lastname: Hartmann
authors.forename: Joachim
authors.initials: J
authors.lastname: Granzin
authors.forename: Matthias
authors.initials: M
authors.lastname: Stoldt
authors.forename: Peter
authors.initials: P
authors.lastname: Henklein
authors.forename: Oliver P
authors.initials: OP
authors.lastname: Ernst
authors.forename: Martin
authors.initials: M
authors.lastname: Heck
authors.forename: Dieter
authors.initials: D
authors.lastname: Willbold
authors.forename: Bernd W
authors.initials: BW
authors.lastname: Koenig
mesh_terms: D019393:Arrestin / Q000737:chemistry*; D008958:Models, Molecular; D019906:Nuclear Magnetic Resonance, Biomolecular; D010777:Photochemistry; D011487:Protein Conformation; D012243:Rhodopsin / Q000737:chemistry*
chemical_list: D019393:Arrestin; D012243:Rhodopsin