 |
|
Title
|
|
Crystal structure of a G-protein beta gamma dimer at 2.1A resolution.
|
|
|
Authors
|
|
J.Sondek,
A.Bohm,
D.G.Lambright,
H.E.Hamm,
P.B.Sigler.
|
|
|
Ref.
|
|
Nature, 1996,
379,
369-374.
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
Many signalling cascades use seven-helical transmembrane receptors coupled to
heterotrimeric G proteins (G alpha beta gamma) to convert extracellular signals
into intracellular responses. Upon nucleotide exchange catalysed by activated
receptors, heterotrimers dissociate into GTP-bound G alpha subunits and G beta
gamma dimers, either of which can modulate many downstream effectors. Here we
use multiwavelength anomalous diffraction data to solve the crystal structure of
the beta gamma dimer of the G protein transducin. The beta-subunit is primarily
a seven-bladed beta-propeller that is partially encircled by an extended
gamma-subunit. The beta-propeller, which contains seven structurally similar WD
repeats, defines the stereochemistry of the WD repeat and the probable
architecture of all WD-repeat-containing domains. The structure details
interactions between G protein beta- and gamma-subunits and highlights regions
implicated in effector modulation for the conserved family of G protein beta
gamma dimers.
|
|
|
|