6EZE

The open conformation of E.coli Elongation Factor Tu in complex with GDPNP.

Summary for 6EZE

• Entry DOI: 10.2210/pdb6eze/pdb
• Descriptor: Elongation factor Tu 2, PHOSPHOAMINOPHOSPHONIC ACID-GUANYLATE ESTER, MAGNESIUM ION, ... (7 entities in total)
• Functional Keywords: elongation factor g-protein, translation
• Biological source: Escherichia coli (strain K12)
• Total number of polymer chains: 2
• Total formula weight: 89181.26

Authors

Johansen, J.S.,Blaise, M.,Thirup, S.S. (deposition date: 2017-11-15, release date: 2018-08-22, Last modification date: 2024-01-17)

Primary citation

Johansen, J.S.,Kavaliauskas, D.,Pfeil, S.H.,Blaise, M.,Cooperman, B.S.,Goldman, Y.E.,Thirup, S.S.,Knudsen, C.R.
E. coli elongation factor Tu bound to a GTP analogue displays an open conformation equivalent to the GDP-bound form.
Nucleic Acids Res., 46:8641-8650, 2018

PubMed Abstract: According to the traditional view, GTPases act as molecular switches, which cycle between distinct 'on' and 'off' conformations bound to GTP and GDP, respectively. Translation elongation factor EF-Tu is a GTPase essential for prokaryotic protein synthesis. In its GTP-bound form, EF-Tu delivers aminoacylated tRNAs to the ribosome as a ternary complex. GTP hydrolysis is thought to cause the release of EF-Tu from aminoacyl-tRNA and the ribosome due to a dramatic conformational change following Pi release. Here, the crystal structure of Escherichia coli EF-Tu in complex with a non-hydrolysable GTP analogue (GDPNP) has been determined. Remarkably, the overall conformation of EF-Tu·GDPNP displays the classical, open GDP-bound conformation. This is in accordance with an emerging view that the identity of the bound guanine nucleotide is not 'locking' the GTPase in a fixed conformation. Using a single-molecule approach, the conformational dynamics of various ligand-bound forms of EF-Tu were probed in solution by fluorescence resonance energy transfer. The results suggest that EF-Tu, free in solution, may sample a wider set of conformations than the structurally well-defined GTP- and GDP-forms known from previous X-ray crystallographic studies. Only upon binding, as a ternary complex, to the mRNA-programmed ribosome, is the well-known, closed GTP-bound conformation, observed.

PubMed: 30107565
DOI: 10.1093/nar/gky697

Experimental method

X-RAY DIFFRACTION (2.47 Å)