1g4r
From Proteopedia
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CRYSTAL STRUCTURE OF BOVINE BETA-ARRESTIN 1
Overview
BACKGROUND: Arrestins are responsible for the desensitization of many sequence-divergent G protein-coupled receptors. They compete with G proteins for binding to activated phosphorylated receptors, initiate receptor internalization, and activate additional signaling pathways. RESULTS: In order to understand the structural basis for receptor binding and arrestin's function as an adaptor molecule, we determined the X-ray crystal structure of two truncated forms of bovine beta-arrestin in its cytosolic inactive state to 1.9 A. Mutational analysis and chimera studies identify the regions in beta-arrestin responsible for receptor binding specificity. beta-arrestin demonstrates high structural homology with the previously solved visual arrestin. All key structural elements responsible for arrestin's mechanism of activation are conserved. CONCLUSIONS: Based on structural analysis and mutagenesis data, we propose a previously unappreciated part in beta-arrestin's mode of action by which a cationic amphipathic helix may function as a reversible membrane anchor. This novel activation mechanism would facilitate the formation of a high-affinity complex between beta-arrestin and an activated receptor regardless of its specific subtype. Like the interaction between beta-arrestin's polar core and the phosphorylated receptor, such a general activation mechanism would contribute to beta-arrestin's versatility as a regulator of many receptors.
About this Structure
1G4R is a Single protein structure of sequence from Bos taurus. Full crystallographic information is available from OCA.
Reference
Crystal structure of beta-arrestin at 1.9 A: possible mechanism of receptor binding and membrane Translocation., Han M, Gurevich VV, Vishnivetskiy SA, Sigler PB, Schubert C, Structure. 2001 Sep;9(9):869-80. PMID:11566136
Page seeded by OCA on Thu Feb 21 12:46:03 2008
