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PubMed · 8939740

An alpha to beta conformational switch in EF-Tu.

K Abel·M D Yoder·R Hilgenfeld·F Jurnak
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Abstract

BACKGROUND: The bacterial elongation factor EF-Tu recognizes and transports aminoacyl-tRNAs to mRNA-programmed ribosomes. EF-Tu shares many structural and functional properties with other GTPases whose conformations are regulated by guanine nucleotides. RESULTS: An intact form of Escherichia coli EF-Tu complexed with GDP has been crystallized in the presence of the EF-Tu-specific antibiotic GE2270 A. The three-dimensional structure has been solved by X-ray diffraction analysis and refined to a final crystallographic R factor of 17.2% at a resolution of 2.5 A. The location of the GE2270 A antibiotic-binding site could not be identified. CONCLUSIONS: The structure of EF-Tu-GDP is nearly identical to that of a trypsin-modified form of EF-Tu-GDP, demonstrating conclusively that the protease treatment had not altered any essential structural features. The present structure represents the first view of an ordered Switch I region in EF-Tu-GDP and reveals similarities with two other GTPases complexed with GDP: Ran and ADP-ribosylation factor-1. A comparison of the Switch I regions of the GTP and GDP forms of EF-Tu also reveals that a segment, six amino acids in length, completely converts from an alpha helix in the GTP complex to beta secondary structure in the GDP form. The alpha to beta switch in EF-Tu may represent a prototypical activation mechanism for other protein families.

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Anti-Bacterial AgentsBacterial ProteinsCrystallography, X-RayEscherichia coliGTP Phosphohydrolase-Linked Elongation FactorsGuanosine DiphosphateGuanosine TriphosphatePeptide Elongation Factor TuPeptides, CyclicProtein ConformationSpecies SpecificityThiazolesComparative StudyJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, P.H.S.

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K Abel, M D Yoder, R Hilgenfeld, F Jurnak. 1996-10-15. An alpha to beta conformational switch in EF-Tu.. https://doi.org/10.1016/s0969-2126(96)00123-2

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