1tui

From Proteopedia

proteopedia linkproteopedia link

spinqualitylabelsall models 1tui, resolution 2.7Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

INTACT ELONGATION FACTOR TU IN COMPLEX WITH GDP

Overview

BACKGROUND: Elongation factor Tu (EF-Tu) in its GTP conformation is a, carrier of aminoacylated tRNAs (aa-tRNAs) to the ribosomal A site during, protein biosynthesis. The ribosome triggers GTP hydrolysis, resulting in, the dissociation of EF-Tu-GDP from the ribosome. The affinity of EF-Tu for, other molecules involved in this process, some of which are unknown, is, regulated by two regions (Switch I and Switch II) that have different, conformations in the GTP and GDP forms. The structure of the GDP form of, EF-Tu is known only as a trypsin-modified fragment, which lacks the Switch, I, or effector, domain. The aim of this work was to establish the overall, structure of intact EF-Tu-GDP, in particular the structure of the effector, domain. RESULTS: The crystal structures of intact EF-Tu-GDP from Thermus, aquaticus and Escherichia coli have been determined at resolutions of 2.7, A and 3.8 A, respectively. The structures confirm the domain orientation, previously found in the structure of partially trypsin-digested EF-Tu-GDP., The structures of the effector region in T. aquaticus and E. coli, EF-Tu-GDP are very similar. The C-terminal part of the effector region of, EF-Tu-GDP is a beta hairpin; in EF-Tu-GTP, this region forms an alpha, helix. This conformational change is not a consequence of crystal packing., CONCLUSIONS: EF-Tu undergoes major conformational changes upon GTP, hydrolysis. Unlike other GTP-binding proteins, EF-Tu exhibits a dramatic, conformational change in the effector region, involving an unwinding of a, small helix and the formation of a beta hairpin structure. This change is, presumably involved in triggering the release of tRNA, and EF-Tu, from the, ribosome.

About this Structure

1TUI is a Single protein structure of sequence from Thermus aquaticus with MG and GDP as ligands. The following page contains interesting information on the relation of 1TUI with [Elongation Factors]. Full crystallographic information is available from OCA.

Reference

Helix unwinding in the effector region of elongation factor EF-Tu-GDP., Polekhina G, Thirup S, Kjeldgaard M, Nissen P, Lippmann C, Nyborg J, Structure. 1996 Oct 15;4(10):1141-51. PMID:8939739

Page seeded by OCA on Sun Nov 18 09:06:43 2007