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1oix
From Proteopedia
| 1oix, resolution 1.70Å () | |||||||||
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| Sites: | , , and | ||||||||
| Ligands: | , , , | ||||||||
| Related: | 1oiv, 1oiw | ||||||||
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| Resources: | FirstGlance, OCA, PDBsum, RCSB | ||||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||||
X-RAY STRUCTURE OF THE SMALL G PROTEIN RAB11A IN COMPLEX WITH GDP AND PI
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.
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
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
About this Structure
1oix is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA.
Reference
- Pasqualato S, Cherfils J. Crystallographic evidence for substrate-assisted GTP hydrolysis by a small GTP binding protein. Structure. 2005 Apr;13(4):533-40. PMID:15837192 doi:10.1016/j.str.2005.01.014
- Pasqualato S, Senic-Matuglia F, Renault L, Goud B, Salamero J, Cherfils J. The structural GDP/GTP cycle of Rab11 reveals a novel interface involved in the dynamics of recycling endosomes. J Biol Chem. 2004 Mar 19;279(12):11480-8. Epub 2003 Dec 29. PMID:14699104 doi:10.1074/jbc.M310558200
