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1gia

From Proteopedia

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[[Image:1gia.jpg|left|200px]]
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[[Image:1gia.png|left|200px]]
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==Overview==
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{{ABSTRACT_8073283}}
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Mechanisms of guanosine triphosphate (GTP) hydrolysis by members of the G protein alpha subunit-p21ras superfamily of guanosine triphosphatases have been studied extensively but have not been well understood. High-resolution x-ray structures of the GTP gamma S and GDP.AlF4- complexes formed by the G protein Gi alpha 1 demonstrate specific roles in transition-state stabilization for two highly conserved residues. Glutamine204 (Gln61 in p21ras) stabilizes and orients the hydrolytic water in the trigonal-bipyramidal transition state. Arginine 178 stabilizes the negative charge at the equatorial oxygen atoms of the pentacoordinate phosphate intermediate. Conserved only in the G alpha family, this residue may account for the higher hydrolytic rate of G alpha proteins relative to those of the p21ras family members. The fold of Gi alpha 1 differs from that of the homologous Gt alpha subunit in the conformation of a helix-loop sequence located in the alpha-helical domain that is characteristic of these proteins; this site may participate in effector binding. The amino-terminal 33 residues are disordered in GTP gamma S-Gi alpha 1, suggesting a mechanism that may promote release of the beta gamma subunit complex when the alpha subunit is activated by GTP.
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==About this Structure==
==About this Structure==
1GIA is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. The following page contains interesting information on the relation of 1GIA with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb58_1.html G Proteins]]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GIA OCA].
1GIA is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Rattus_norvegicus Rattus norvegicus]. The following page contains interesting information on the relation of 1GIA with [[http://pdb.rcsb.org/pdb/static.do?p=education_discussion/molecule_of_the_month/pdb58_1.html G Proteins]]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GIA OCA].
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==Reference==
 
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Structures of active conformations of Gi alpha 1 and the mechanism of GTP hydrolysis., Coleman DE, Berghuis AM, Lee E, Linder ME, Gilman AG, Sprang SR, Science. 1994 Sep 2;265(5177):1405-12. PMID:[http://www.ncbi.nlm.nih.gov/pubmed/8073283 8073283]
 
[[Category: G Proteins]]
[[Category: G Proteins]]
[[Category: Rattus norvegicus]]
[[Category: Rattus norvegicus]]
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[[Category: Sprang, S R.]]
[[Category: Sprang, S R.]]
[[Category: Signal transduction protein]]
[[Category: Signal transduction protein]]
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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May 2 17:36:35 2008''
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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Jun 26 17:25:40 2008''

Revision as of 14:25, 26 June 2008

Image:1gia.png

Template:STRUCTURE 1gia

STRUCTURE OF ACTIVE CONFORMATIONS OF GIA1 AND THE MECHANISM OF GTP HYDROLYSIS


Template:ABSTRACT 8073283

About this Structure

1GIA is a Single protein structure of sequence from Rattus norvegicus. The following page contains interesting information on the relation of 1GIA with [G Proteins]. Full crystallographic information is available from OCA.

Page seeded by OCA on Thu Jun 26 17:25:40 2008

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OCA

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