1oix

X-RAY STRUCTURE OF THE SMALL G PROTEIN RAB11A IN COMPLEX WITH GDP AND PI

spinqualitylabelsall models 1oix, resolution 1.70Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 1oix is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: CL, GDP, MG, PO4 Related: 1oiv, 1oiw Resources: FirstGlance, OCA, RCSB, PDBsum Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed 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.

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