1oix

From Proteopedia

Revision as of 10:15, 30 October 2007

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 ... [(full description)]

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

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