1oix
From Proteopedia
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==Overview== | ==Overview== | ||
| - | GTP hydrolysis by small GTP binding proteins of the Ras superfamily is a, universal reaction that controls multiple cellular regulations. Its, enzymic mechanism has been the subject of long-standing debates as to the, existence/identity of the general base and the electronic nature of its, transition state. Here we report the high-resolution crystal structure of, a small GTP binding protein, Rab11, solved in complex with GDP and Pi., Unexpectedly, a Pi oxygen and the GDP-cleaved oxygen are located less than, 2.5 A apart, suggesting that they share a proton, likely in the form of a, low-barrier hydrogen bond. This implies that the gamma-phosphate of GTP, was protonated; hence, that GTP acts as a general base. Furthermore, this, interaction should establish at, and stabilize, the transition .. | + | GTP hydrolysis by small GTP binding proteins of the Ras superfamily is a, universal reaction that controls multiple cellular regulations. Its, enzymic mechanism has been the subject of long-standing debates as to the, existence/identity of the general base and the electronic nature of its, transition state. Here we report the high-resolution crystal structure of, a small GTP binding protein, Rab11, solved in complex with GDP and Pi., Unexpectedly, a Pi oxygen and the GDP-cleaved oxygen are located less than, 2.5 A apart, suggesting that they share a proton, likely in the form of a, low-barrier hydrogen bond. This implies that the gamma-phosphate of GTP, was protonated; hence, that GTP acts as a general base. Furthermore, this, interaction should establish at, and stabilize, the transition state., Altogether, we propose a revised model for the GTPase reaction that should, reconcile earlier models into a unique substrate-assisted mechanism. |
==About this Structure== | ==About this Structure== | ||
| - | 1OIX is a | + | 1OIX 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 PO4, MG, CL and GDP as [http://en.wikipedia.org/wiki/ligands ligands]. Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1OIX OCA]. |
==Reference== | ==Reference== | ||
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[[Category: small g protein]] | [[Category: small g protein]] | ||
| - | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | + | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 13:53:38 2007'' |
Revision as of 11:48, 5 November 2007
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X-RAY STRUCTURE OF THE SMALL G PROTEIN RAB11A IN COMPLEX WITH GDP AND PI
Overview
GTP hydrolysis by small GTP binding proteins of the Ras superfamily is a, universal reaction that controls multiple cellular regulations. Its, enzymic mechanism has been the subject of long-standing debates as to the, existence/identity of the general base and the electronic nature of its, transition state. Here we report the high-resolution crystal structure of, a small GTP binding protein, Rab11, solved in complex with GDP and Pi., Unexpectedly, a Pi oxygen and the GDP-cleaved oxygen are located less than, 2.5 A apart, suggesting that they share a proton, likely in the form of a, low-barrier hydrogen bond. This implies that the gamma-phosphate of GTP, was protonated; hence, that GTP acts as a general base. Furthermore, this, interaction should establish at, and stabilize, the transition state., Altogether, we propose a revised model for the GTPase reaction that should, reconcile earlier models into a unique substrate-assisted mechanism.
About this Structure
1OIX is a Single protein structure of sequence from Homo sapiens with PO4, MG, CL and GDP as ligands. Structure known Active Site: AC1. Full crystallographic information is available from OCA.
Reference
Crystallographic evidence for substrate-assisted GTP hydrolysis by a small GTP binding protein., Pasqualato S, Cherfils J, Structure. 2005 Apr;13(4):533-40. PMID:15837192
Page seeded by OCA on Mon Nov 5 13:53:38 2007
Categories: Homo sapiens | Single protein | Cherfils, J. | Goud, B. | Pasqualato, S. | Renault, L. | Salamero, J. | Senic-Matuglia, F. | CL | GDP | MG | PO4 | Gtp-binding | Intracellular trafficking | Lipoprotein | Prenylation | Protein transport | Small g protein
