1azt
From Proteopedia
GS-ALPHA COMPLEXED WITH GTP-GAMMA-S
Structural highlights
FunctionGNAS2_BOVIN Guanine nucleotide-binding proteins (G proteins) are involved as modulators or transducers in various transmembrane signaling systems. The G(s) protein is involved in hormonal regulation of adenylate cyclase: it activates the cyclase in response to beta-adrenergic stimuli. Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe crystal structure of Gsalpha, the heterotrimeric G protein alpha subunit that stimulates adenylyl cyclase, was determined at 2.5 A in a complex with guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS). Gsalpha is the prototypic member of a family of GTP-binding proteins that regulate the activities of effectors in a hormone-dependent manner. Comparison of the structure of Gsalpha.GTPgammaS with that of Gialpha.GTPgammaS suggests that their effector specificity is primarily dictated by the shape of the binding surface formed by the switch II helix and the alpha3-beta5 loop, despite the high sequence homology of these elements. In contrast, sequence divergence explains the inability of regulators of G protein signaling to stimulate the GTPase activity of Gsalpha. The betagamma binding surface of Gsalpha is largely conserved in sequence and structure to that of Gialpha, whereas differences in the surface formed by the carboxyl-terminal helix and the alpha4-beta6 loop may mediate receptor specificity. Crystal structure of the adenylyl cyclase activator Gsalpha.,Sunahara RK, Tesmer JJ, Gilman AG, Sprang SR Science. 1997 Dec 12;278(5345):1943-7. PMID:9395396[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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