1kao
From Proteopedia
(New page: 200px<br /> <applet load="1kao" size="450" color="white" frame="true" align="right" spinBox="true" caption="1kao, resolution 1.7Å" /> '''CRYSTAL STRUCTURE OF...) |
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| - | [[Image:1kao.gif|left|200px]]<br /> | + | [[Image:1kao.gif|left|200px]]<br /><applet load="1kao" size="350" color="white" frame="true" align="right" spinBox="true" |
| - | <applet load="1kao" size=" | + | |
caption="1kao, resolution 1.7Å" /> | caption="1kao, resolution 1.7Å" /> | ||
'''CRYSTAL STRUCTURE OF THE SMALL G PROTEIN RAP2A WITH GDP'''<br /> | '''CRYSTAL STRUCTURE OF THE SMALL G PROTEIN RAP2A WITH GDP'''<br /> | ||
==Overview== | ==Overview== | ||
| - | The small G protein Rap2A has been crystallized in complex with GDP, GTP | + | The small G protein Rap2A has been crystallized in complex with GDP, GTP and GTPgammaS. The Rap2A-GTP complex is the first structure of a small G protein with its natural ligand GTP. It shows that the hydroxyl group of Tyr32 forms a hydrogen bond with the gamma-phosphate of GTP and with Gly13. This interaction does not exist in the Rap2A-GTPgammaS complex. Tyr32 is conserved in many small G proteins, which probably also form this hydrogen bond with GTP. In addition, Tyr32 is structurally equivalent to a conserved arginine that binds GTP in trimeric G proteins. The actual participation of Tyr32 in GTP hydrolysis is not yet clear, but several possible roles are discussed. The conformational changes between the GDP and GTP complexes are located essentially in the switch I and II regions as described for the related oncoprotein H-Ras. However, the mobile segments vary in length and in the amplitude of movement. This suggests that even though similar regions might be involved in the GDP-GTP cycle of small G proteins, the details of the changes will be different for each G protein and will ensure the specificity of its interaction with a given set of cellular proteins. |
==About this Structure== | ==About this Structure== | ||
| - | 1KAO is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with MG and GDP as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1KAO is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens] with <scene name='pdbligand=MG:'>MG</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=1KAO OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Homo sapiens]] | [[Category: Homo sapiens]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Bras, G | + | [[Category: Bras, G Le.]] |
[[Category: Cherfils, J.]] | [[Category: Cherfils, J.]] | ||
[[Category: Menetrey, J.]] | [[Category: Menetrey, J.]] | ||
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[[Category: small g protein]] | [[Category: small g protein]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 13:31:58 2008'' |
Revision as of 11:32, 21 February 2008
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CRYSTAL STRUCTURE OF THE SMALL G PROTEIN RAP2A WITH GDP
Overview
The small G protein Rap2A has been crystallized in complex with GDP, GTP and GTPgammaS. The Rap2A-GTP complex is the first structure of a small G protein with its natural ligand GTP. It shows that the hydroxyl group of Tyr32 forms a hydrogen bond with the gamma-phosphate of GTP and with Gly13. This interaction does not exist in the Rap2A-GTPgammaS complex. Tyr32 is conserved in many small G proteins, which probably also form this hydrogen bond with GTP. In addition, Tyr32 is structurally equivalent to a conserved arginine that binds GTP in trimeric G proteins. The actual participation of Tyr32 in GTP hydrolysis is not yet clear, but several possible roles are discussed. The conformational changes between the GDP and GTP complexes are located essentially in the switch I and II regions as described for the related oncoprotein H-Ras. However, the mobile segments vary in length and in the amplitude of movement. This suggests that even though similar regions might be involved in the GDP-GTP cycle of small G proteins, the details of the changes will be different for each G protein and will ensure the specificity of its interaction with a given set of cellular proteins.
About this Structure
1KAO is a Single protein structure of sequence from Homo sapiens with and as ligands. Full crystallographic information is available from OCA.
Reference
Crystal structures of the small G protein Rap2A in complex with its substrate GTP, with GDP and with GTPgammaS., Cherfils J, Menetrey J, Le Bras G, Janoueix-Lerosey I, de Gunzburg J, Garel JR, Auzat I, EMBO J. 1997 Sep 15;16(18):5582-91. PMID:9312017
Page seeded by OCA on Thu Feb 21 13:31:58 2008
Categories: Homo sapiens | Single protein | Bras, G Le. | Cherfils, J. | Menetrey, J. | GDP | MG | Gdp | Gtp-binding protein | Rap2 | Ras | Small g protein
