1aqg
From Proteopedia
(New page: 200px<br /><applet load="1aqg" size="450" color="white" frame="true" align="right" spinBox="true" caption="1aqg" /> '''NMR STRUCTURE OF THE RHODOPSIN-BOUND C-TERMI...) |
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| - | [[Image:1aqg.jpg|left|200px]]<br /><applet load="1aqg" size=" | + | [[Image:1aqg.jpg|left|200px]]<br /><applet load="1aqg" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1aqg" /> | caption="1aqg" /> | ||
'''NMR STRUCTURE OF THE RHODOPSIN-BOUND C-TERMINAL PEPTIDE OF THE TRANSDUCIN ALPHA-SUBUNIT, 20 STRUCTURES'''<br /> | '''NMR STRUCTURE OF THE RHODOPSIN-BOUND C-TERMINAL PEPTIDE OF THE TRANSDUCIN ALPHA-SUBUNIT, 20 STRUCTURES'''<br /> | ||
==Overview== | ==Overview== | ||
| - | A large superfamily of transmembrane receptors control cellular responses | + | A large superfamily of transmembrane receptors control cellular responses to diverse extracellular signals by catalyzing activation of specific types of heterotrimeric GTP-binding proteins. How these receptors recognize and promote nucleotide exchange on G protein alpha subunits to initiate signal amplification is unknown. The three-dimensional structure of the transducin (Gt) alpha subunit C-terminal undecapeptide Gtalpha(340-350) IKENLKDCGLF was determined by transferred nuclear Overhauser effect spectroscopy while it was bound to photoexcited rhodopsin. Light activation of rhodopsin causes a dramatic shift from a disordered conformation of Gtalpha(340-350) to a binding motif with a helical turn followed by an open reverse turn centered at Gly-348, a helix-terminating C capping motif of an alphaL type. Docking of the NMR structure to the GDP-bound x-ray structure of Gt reveals that photoexcited rhodopsin promotes the formation of a continuous helix over residues 325-346 terminated by the C-terminal helical cap with a unique cluster of crucial hydrophobic side chains. A molecular mechanism by which activated receptors can control G proteins through reversible conformational changes at the receptor-G protein interface is demonstrated. |
==About this Structure== | ==About this Structure== | ||
| - | 1AQG is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http:// | + | 1AQG is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1AQG OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Bos taurus]] | [[Category: Bos taurus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Kisselev, O | + | [[Category: Kisselev, O G.]] |
| - | [[Category: Marshall, G | + | [[Category: Marshall, G R.]] |
[[Category: gtp-binding]] | [[Category: gtp-binding]] | ||
[[Category: rhodopsin]] | [[Category: rhodopsin]] | ||
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[[Category: transducin]] | [[Category: transducin]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 11:47:13 2008'' |
Revision as of 09:47, 21 February 2008
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NMR STRUCTURE OF THE RHODOPSIN-BOUND C-TERMINAL PEPTIDE OF THE TRANSDUCIN ALPHA-SUBUNIT, 20 STRUCTURES
Overview
A large superfamily of transmembrane receptors control cellular responses to diverse extracellular signals by catalyzing activation of specific types of heterotrimeric GTP-binding proteins. How these receptors recognize and promote nucleotide exchange on G protein alpha subunits to initiate signal amplification is unknown. The three-dimensional structure of the transducin (Gt) alpha subunit C-terminal undecapeptide Gtalpha(340-350) IKENLKDCGLF was determined by transferred nuclear Overhauser effect spectroscopy while it was bound to photoexcited rhodopsin. Light activation of rhodopsin causes a dramatic shift from a disordered conformation of Gtalpha(340-350) to a binding motif with a helical turn followed by an open reverse turn centered at Gly-348, a helix-terminating C capping motif of an alphaL type. Docking of the NMR structure to the GDP-bound x-ray structure of Gt reveals that photoexcited rhodopsin promotes the formation of a continuous helix over residues 325-346 terminated by the C-terminal helical cap with a unique cluster of crucial hydrophobic side chains. A molecular mechanism by which activated receptors can control G proteins through reversible conformational changes at the receptor-G protein interface is demonstrated.
About this Structure
1AQG is a Single protein structure of sequence from Bos taurus. Full crystallographic information is available from OCA.
Reference
Light-activated rhodopsin induces structural binding motif in G protein alpha subunit., Kisselev OG, Kao J, Ponder JW, Fann YC, Gautam N, Marshall GR, Proc Natl Acad Sci U S A. 1998 Apr 14;95(8):4270-5. PMID:9539726
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