1ctq
From Proteopedia
(New page: 200px<br /> <applet load="1ctq" size="450" color="white" frame="true" align="right" spinBox="true" caption="1ctq, resolution 1.26Å" /> '''STRUCTURE OF P21RAS...) |
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caption="1ctq, resolution 1.26Å" /> | caption="1ctq, resolution 1.26Å" /> | ||
'''STRUCTURE OF P21RAS IN COMPLEX WITH GPPNHP AT 100 K'''<br /> | '''STRUCTURE OF P21RAS IN COMPLEX WITH GPPNHP AT 100 K'''<br /> | ||
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==About this Structure== | ==About this Structure== | ||
| - | 1CTQ 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 GNP as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1CTQ 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=GNP:'>GNP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1CTQ OCA]. |
==Reference== | ==Reference== | ||
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[[Category: signaling protein]] | [[Category: signaling protein]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri Feb 15 15:37:09 2008'' |
Revision as of 13:37, 15 February 2008
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STRUCTURE OF P21RAS IN COMPLEX WITH GPPNHP AT 100 K
Contents |
Overview
BACKGROUND: In numerous biological events the hydrolysis of guanine, triphosphate (GTP) is a trigger to switch from the active to the inactive, protein form. In spite of the availability of several high-resolution, crystal structures, the details of the mechanism of nucleotide hydrolysis, by GTPases are still unclear. This is partly because the structures of the, proteins in their active states had to be determined in the presence of, non-hydrolyzable GTP analogues (e.g. GppNHp). Knowledge of the structure, of the true Michaelis complex might provide additional insights into the, intrinsic protein hydrolysis mechanism of GTP and related nucleotides., RESULTS: The structure of the complex formed between p21(ras) and GTP has, been determined by X-ray diffraction at 1.6 A using a combination of, photolysis of an inactive GTP precursor (caged GTP) and rapid freezing, (100K). The structure of this complex differs from that of p21(ras)-GppNHp, (determined at 277K) with respect to the degree of order and conformation, of the catalytic loop (loop 4 of the switch II region) and the positioning, of water molecules around the gamma-phosphate group. The changes in the, arrangement of water molecules were induced by the cryo-temperature, technique. CONCLUSIONS: The results shed light on the function of Gln61 in, the intrinsic GTP hydrolysis reaction. Furthermore, the possibility of a, proton shuffling mechanism between two attacking water molecules and an, oxygen of the gamma-phosphate group can be proposed for the basal GTPase, mechanism, but arguments are presented that render this protonation, mechanism unlikely for the GTPase activating protein (GAP)-activated, GTPase.
Disease
Known diseases associated with this structure: Bladder cancer, somatic OMIM:[190020], Costello syndrome OMIM:[190020], Thyroid carcinoma, follicular, somatic OMIM:[190020]
About this Structure
1CTQ is a Single protein structure of sequence from Homo sapiens with and as ligands. Full crystallographic information is available from OCA.
Reference
The pre-hydrolysis state of p21(ras) in complex with GTP: new insights into the role of water molecules in the GTP hydrolysis reaction of ras-like proteins., Scheidig AJ, Burmester C, Goody RS, Structure. 1999 Nov 15;7(11):1311-24. PMID:10574788
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