1b9y
|
STRUCTURAL ANALYSIS OF PHOSDUCIN AND ITS PHOSPHORYLATION-REGULATED INTERACTION WITH TRANSDUCIN BETA-GAMMA
OverviewOverview
Visual signal transduction is a nearly noise-free process that is, exquisitely well regulated over a wide dynamic range of light intensity. A, key component in dark/light adaptation is phosducin, a phosphorylatable, protein that modulates the amount of transducin heterotrimer (Gt alpha, beta gamma) available through sequestration of the beta gamma subunits (Gt, beta gamma). The structure of the phosphophosducin/Gt beta gamma complex, combined with mutational and biophysical analysis provides a, stereochemical mechanism for the regulation of the phosducin-Gt beta gamma, interaction. Phosphorylation of serine 73 causes an order-to-disorder, transition of a 20-residue stretch, including the phosphorylation site, by, disrupting a helix-capping motif. This transition disrupts phosducin's, interface with Gt beta gamma, leading to the release of unencumbered Gt, beta gamma, which reassociates with the membrane and Gt alpha to form a, signaling-competent Gt alpha beta gamma heterotrimer.
About this StructureAbout this Structure
1B9Y is a Protein complex structure of sequences from Bos taurus and Rattus norvegicus with GD as ligand. Full crystallographic information is available from OCA.
ReferenceReference
A molecular mechanism for the phosphorylation-dependent regulation of heterotrimeric G proteins by phosducin., Gaudet R, Savage JR, McLaughlin JN, Willardson BM, Sigler PB, Mol Cell. 1999 May;3(5):649-60. PMID:10360181
Page seeded by OCA on Tue Nov 20 11:29:49 2007