title: Crystal structure of the multifunctional Gbeta5-RGS9 complex.
abstract: Regulators of G-protein signaling (RGS) proteins enhance the intrinsic GTPase activity of G protein alpha (Galpha) subunits and are vital for proper signaling kinetics downstream of G protein-coupled receptors (GPCRs). R7 subfamily RGS proteins specifically and obligately dimerize with the atypical G protein beta5 (Gbeta5) subunit through an internal G protein gamma (Ggamma)-subunit-like (GGL) domain. Here we present the 1.95-A crystal structure of the Gbeta5-RGS9 complex, which is essential for normal visual and neuronal signal transduction. This structure reveals a canonical RGS domain that is functionally integrated within a molecular complex that is poised for integration of multiple steps during G-protein activation and deactivation.
authors.affiliation: Department of Pharmacology, University of North Carolina School of Medicine, Campus Box 7365, Chapel Hill, North Carolina 27599-7365, USA.
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Cheever
authors.forename: Jason T
authors.initials: JT
authors.lastname: Snyder
authors.forename: Svetlana
authors.initials: S
authors.lastname: Gershburg
authors.forename: David P
authors.initials: DP
authors.lastname: Siderovski
authors.forename: T Kendall
authors.initials: TK
authors.lastname: Harden
authors.forename: John
authors.initials: J
authors.lastname: Sondek
mesh_terms: D001665:Binding Sites; D018360:Crystallography, X-Ray; D019281:Dimerization; D044387:GTP-Binding Protein beta Subunits / Q000737:chemistry*; D006801:Humans; D008958:Models, Molecular; D011485:Protein Binding; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D020710:RGS Proteins / Q000737:chemistry*
chemical_list: C490611:GNB5 protein, human; D044387:GTP-Binding Protein beta Subunits; D020710:RGS Proteins; C116925:regulator of g-protein signaling 9