1b9y
STRUCTURAL ANALYSIS OF PHOSDUCIN AND ITS PHOSPHORYLATION-REGULATED INTERACTION WITH TRANSDUCIN BETA-GAMMA
| |||||||
| , resolution 3.00Å | |||||||
|---|---|---|---|---|---|---|---|
| Ligands: | |||||||
| Gene: | RAT PDC (Rattus norvegicus) | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
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. 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 Thu Mar 20 10:08:15 2008