1FQK

CRYSTAL STRUCTURE OF THE HETERODIMERIC COMPLEX OF THE RGS DOMAIN OF RGS9, AND THE GT/I1 CHIMERA ALPHA SUBUNIT [(RGS9)-(GT/I1ALPHA)-(GDP)-(ALF4-)-(MG2+)]

Summary for 1FQK

• Entry DOI: 10.2210/pdb1fqk/pdb
• Related: 1fqi 1FQJ
• Descriptor: Guanine nucleotide-binding protein G(t) subunit alpha-1,Guanine nucleotide-binding protein G(i) subunit alpha-1,Guanine nucleotide-binding protein G(t) subunit alpha-1, Regulator of G-protein signaling 9, MAGNESIUM ION, ... (6 entities in total)
• Functional Keywords: rgs9, transducin, g protein, phototransduction, rod, rgs, gap, signaling protein
• Biological source: Bos taurus (Bovine); More
• Cellular location: Membrane; Peripheral membrane protein: O46469
• Total number of polymer chains: 4
• Total formula weight: 110702.63

Authors

Slep, K.C.,Kercher, M.A.,He, W.,Cowan, C.W.,Wensel, T.G.,Sigler, P.B. (deposition date: 2000-09-05, release date: 2001-02-28, Last modification date: 2024-02-07)

Primary citation

Slep, K.C.,Kercher, M.A.,He, W.,Cowan, C.W.,Wensel, T.G.,Sigler, P.B.
Structural determinants for regulation of phosphodiesterase by a G protein at 2.0 A.
Nature, 409:1071-1077, 2001

PubMed Abstract: A multitude of heptahelical receptors use heterotrimeric G proteins to transduce signals to specific effector target molecules. The G protein transducin, Gt, couples photon-activated rhodopsin with the effector cyclic GMP phosophodiesterase (PDE) in the vertebrate phototransduction cascade. The interactions of the Gt alpha-subunit (alpha(t)) with the inhibitory PDE gamma-subunit (PDEgamma) are central to effector activation, and also enhance visual recovery in cooperation with the GTPase-activating protein regulator of G-protein signalling (RGS)-9 (refs 1-3). Here we describe the crystal structure at 2.0 A of rod transducin alpha x GDP x AlF4- in complex with the effector molecule PDEgamma and the GTPase-activating protein RGS9. In addition, we present the independently solved crystal structures of the RGS9 RGS domain both alone and in complex with alpha(t/i1) x GDP x AlF4-. These structures reveal insights into effector activation, synergistic GTPase acceleration, RGS9 specificity and RGS activity. Effector binding to a nucleotide-dependent site on alpha(t) sequesters PDEgamma residues implicated in PDE inhibition, and potentiates recruitment of RGS9 for hydrolytic transition state stabilization and concomitant signal termination.

PubMed: 11234020
DOI: 10.1038/35059138

Experimental method

X-RAY DIFFRACTION (2.3 Å)