1MF6

Transducin gamma subunit, C-terminal domain 60-71, rhodopsin-bound state: Ensemble of 15 models determined by TrNOE spectroscopy

Summary for 1MF6

• Entry DOI: 10.2210/pdb1mf6/pdb
• Descriptor: Guanine nucleotide-binding protein G(T)gamma-T1 subunit (1 entity in total)
• Functional Keywords: g-protein, transducin, rhodopsin, gpcr, gamma subunit, bound conformation, c-terminal domain, signaling protein
• Biological source: Bos taurus (cattle); More
• Cellular location: Cell membrane; Lipid-anchor; Cytoplasmic side (Potential): P02698
• Total number of polymer chains: 1
• Total formula weight: 1338.55

Authors

Kisselev, O.G. (deposition date: 2002-08-09, release date: 2003-04-15, Last modification date: 2024-05-22)

Primary citation

Kisselev, O.G.,Downs, M.A.
RHODOPSIN CONTROLS A CONFORMATIONAL SWITCH ON THE TRANSDUCIN gamma SUBUNIT
Structure, 11:367-373, 2003

PubMed Abstract: Rhodopsin, a prototypical G protein-coupled receptor, catalyzes the activation of a heterotrimeric G protein, transducin, to initiate a visual signaling cascade in photoreceptor cells. The betagamma subunit complex, especially the C-terminal domain of the transducin gamma subunit, Gtgamma(60-71)farnesyl, plays a pivotal role in allosteric regulation of nucleotide exchange on the transducin alpha subunit by light-activated rhodopsin. We report that this domain is unstructured in the presence of an inactive receptor but forms an amphipathic helix upon rhodopsin activation. A K65E/E66K charge reversal mutant of the gamma subunit has diminished interactions with the receptor and fails to adopt the helical conformation. The identification of this conformational switch provides a mechanism for active GPCR utilization of the betagamma complex in signal transfer to G proteins.

PubMed: 12679015
DOI: 10.1016/S0969-2126(03)00045-5

Experimental method

SOLUTION NMR