1tui
From Proteopedia
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| , resolution 2.7Å | |||||||
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| Ligands: | and | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
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. 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 Mar 23 13:47:16 2008
