1B9Y

STRUCTURAL ANALYSIS OF PHOSDUCIN AND ITS PHOSPHORYLATION-REGULATED INTERACTION WITH TRANSDUCIN BETA-GAMMA

Summary for 1B9Y

• Entry DOI: 10.2210/pdb1b9y/pdb
• Descriptor: PROTEIN (TRANSDUCIN), PROTEIN (PHOSDUCIN), GADOLINIUM ATOM, ... (5 entities in total)
• Functional Keywords: phosducin, transducin, beta-gamma, signal transduction, regulation, phosphorylation, g proteins, thioredoxin, vision, meka, complex (transducer- transduction), signaling protein
• Biological source: Rattus norvegicus (Norway rat); More
• Total number of polymer chains: 3
• Total formula weight: 74577.03

Authors

Gaudet, R.,Sigler, P.B. (deposition date: 1999-02-16, release date: 1999-02-23, Last modification date: 2023-08-09)

Primary citation

Gaudet, R.,Savage, J.R.,McLaughlin, J.N.,Willardson, B.M.,Sigler, P.B.
A molecular mechanism for the phosphorylation-dependent regulation of heterotrimeric G proteins by phosducin.
Mol.Cell, 3:649-660, 1999

PubMed Abstract: 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.

PubMed: 10360181
DOI: 10.1016/S1097-2765(00)80358-5

Experimental method

X-RAY DIFFRACTION (3 Å)