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 17.20% at a resolution of 2.5 Å. 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 simulates 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 α helix in the GTP complex to β secondary structure in the GDP form. The α to β switch in EF-Tu may represent a prototypical activation mechanism for other protein families.
| Original language | English |
|---|---|
| Journal | Structure |
| Volume | 4 |
| Issue number | 10 |
| Pages (from-to) | 1153-1159 |
| Number of pages | 7 |
| ISSN | 0969-2126 |
| DOIs | |
| Publication status | Published - 1996 |
Funding
FJ gratefully acknowledges the support of the Public Health Service (GM 26895), the San Diego Supercomputer Center, the Center for Visual Graphics at the University of California, Riverside, and the gift of GE2270 A from LePetit Research Center, Geranzano, Italy. RH gratefully acknowledges the support of the German Federal Research Ministry (BMBF 05641BJA4), the Deutsche Forschungsgemeinschaft (HI 611/1-1), the European Commission (EERBCHRXCT940510) and the Howard Hughes Medical Institute (75195–540701).
Research Areas and Centers
- Academic Focus: Center for Infection and Inflammation Research (ZIEL)
