1tad
From Proteopedia
(New page: 200px<br /><applet load="1tad" size="450" color="white" frame="true" align="right" spinBox="true" caption="1tad, resolution 1.7Å" /> '''GTPASE MECHANISM OF G...) |
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| - | [[Image:1tad.gif|left|200px]]<br /><applet load="1tad" size=" | + | [[Image:1tad.gif|left|200px]]<br /><applet load="1tad" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1tad, resolution 1.7Å" /> | caption="1tad, resolution 1.7Å" /> | ||
'''GTPASE MECHANISM OF GPROTEINS FROM THE 1.7-ANGSTROM CRYSTAL STRUCTURE OF TRANSDUCIN ALPHA-GDP-ALF4-'''<br /> | '''GTPASE MECHANISM OF GPROTEINS FROM THE 1.7-ANGSTROM CRYSTAL STRUCTURE OF TRANSDUCIN ALPHA-GDP-ALF4-'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Aluminium fluoride (AIF-4) activates members of the heterotrimeric | + | Aluminium fluoride (AIF-4) activates members of the heterotrimeric G-protein (G alpha beta gamma) family by binding to inactive G alpha.GDP near the site occupied by the gamma-phosphate in G alpha.GTP (ref. 3). Here we describe the crystal structure of transducin alpha.GDP activated with aluminium fluoride (Gt alpha.GDP.AIF-4.H2O) at 1.7 A, a resolution sufficient to establish the coordination geometry of the bound aluminium fluoride as well as the extensive network of direct and water-mediated interactions that stabilize it. These observations are derived from three independent representations in the asymmetric unit, eliminating any chance of drawing conclusions based on stereochemistry imposed by crystal packing. Surprisingly, aluminium fluoride activates G alpha.GDP by binding with a geometry resembling a pentavalent intermediate for GTP hydrolysis. The stabilizing interactions involve not only residues that interact with the gamma-phosphate in Gt alpha.GTP gamma S, but also conserved residues for GTPase activity. Thus the Gt alpha.GDP.AIF-4.H2O structure provides new insight into the mechanism of GTP hydrolysis. |
==About this Structure== | ==About this Structure== | ||
| - | 1TAD is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with CA, CAC, ALF and GDP as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1TAD is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with <scene name='pdbligand=CA:'>CA</scene>, <scene name='pdbligand=CAC:'>CAC</scene>, <scene name='pdbligand=ALF:'>ALF</scene> and <scene name='pdbligand=GDP:'>GDP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1TAD OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Bos taurus]] | [[Category: Bos taurus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Hamm, H | + | [[Category: Hamm, H E.]] |
| - | [[Category: Lambright, D | + | [[Category: Lambright, D G.]] |
| - | [[Category: Noel, J | + | [[Category: Noel, J P.]] |
| - | [[Category: Sigler, P | + | [[Category: Sigler, P B.]] |
[[Category: Sondek, J.]] | [[Category: Sondek, J.]] | ||
[[Category: ALF]] | [[Category: ALF]] | ||
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[[Category: gtp-binding protein]] | [[Category: gtp-binding protein]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:11:35 2008'' |
Revision as of 13:11, 21 February 2008
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GTPASE MECHANISM OF GPROTEINS FROM THE 1.7-ANGSTROM CRYSTAL STRUCTURE OF TRANSDUCIN ALPHA-GDP-ALF4-
Overview
Aluminium fluoride (AIF-4) activates members of the heterotrimeric G-protein (G alpha beta gamma) family by binding to inactive G alpha.GDP near the site occupied by the gamma-phosphate in G alpha.GTP (ref. 3). Here we describe the crystal structure of transducin alpha.GDP activated with aluminium fluoride (Gt alpha.GDP.AIF-4.H2O) at 1.7 A, a resolution sufficient to establish the coordination geometry of the bound aluminium fluoride as well as the extensive network of direct and water-mediated interactions that stabilize it. These observations are derived from three independent representations in the asymmetric unit, eliminating any chance of drawing conclusions based on stereochemistry imposed by crystal packing. Surprisingly, aluminium fluoride activates G alpha.GDP by binding with a geometry resembling a pentavalent intermediate for GTP hydrolysis. The stabilizing interactions involve not only residues that interact with the gamma-phosphate in Gt alpha.GTP gamma S, but also conserved residues for GTPase activity. Thus the Gt alpha.GDP.AIF-4.H2O structure provides new insight into the mechanism of GTP hydrolysis.
About this Structure
1TAD is a Single protein structure of sequence from Bos taurus with , , and as ligands. Full crystallographic information is available from OCA.
Reference
GTPase mechanism of Gproteins from the 1.7-A crystal structure of transducin alpha-GDP-AIF-4., Sondek J, Lambright DG, Noel JP, Hamm HE, Sigler PB, Nature. 1994 Nov 17;372(6503):276-9. PMID:7969474
Page seeded by OCA on Thu Feb 21 15:11:35 2008
Categories: Bos taurus | Single protein | Hamm, H E. | Lambright, D G. | Noel, J P. | Sigler, P B. | Sondek, J. | ALF | CA | CAC | GDP | Gtp-binding protein
