Elongation Factor Ts Directly Facilitates the Formation and Disassembly of the Escherichia coli Elongation Factor Tu·GTP·Aminoacyl-tRNA Ternary Complex*
| Autor: | Ryan Ferrao, Scott C. Blanchard, Jose L. Alejo, Roger B. Altman, Benjamin J. Burnett, Navdep Kaur, Joshua Kanji |
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| Jazyk: | angličtina |
| Rok vydání: | 2013 |
| Předmět: |
Models
Molecular Conformational change GTP' Guanosine Guanosine triphosphate Biology Peptide Elongation Factor Tu RNA Transfer Amino Acyl Biochemistry Protein Structure Secondary Nucleotide exchange factor chemistry.chemical_compound Escherichia coli Protein Structure Quaternary Molecular Biology Ternary complex Aminoacyl-tRNA Binding Sites Protein Stability Escherichia coli Proteins Cell Biology Peptide Elongation Factors Protein Structure Tertiary Kinetics Spectrometry Fluorescence chemistry Protein Synthesis and Degradation Biophysics bacteria Guanosine Triphosphate Protein Multimerization EF-Tu Protein Binding |
| Popis: | Aminoacyl-tRNA (aa-tRNA) enters the ribosome in a ternary complex with the G-protein elongation factor Tu (EF-Tu) and GTP.EF-Tu·GTP·aa-tRNA ternary complex formation and decay rates are accelerated in the presence of the nucleotide exchange factor elongation factor Ts (EF-Ts).EF-Ts directly facilitates the formation and disassociation of ternary complex.This system demonstrates a novel function of EF-Ts. Aminoacyl-tRNA enters the translating ribosome in a ternary complex with elongation factor Tu (EF-Tu) and GTP. Here, we describe bulk steady state and pre-steady state fluorescence methods that enabled us to quantitatively explore the kinetic features of Escherichia coli ternary complex formation and decay. The data obtained suggest that both processes are controlled by a nucleotide-dependent, rate-determining conformational change in EF-Tu. Unexpectedly, we found that this conformational change is accelerated by elongation factor Ts (EF-Ts), the guanosine nucleotide exchange factor for EF-Tu. Notably, EF-Ts attenuates the affinity of EF-Tu for GTP and destabilizes ternary complex in the presence of non-hydrolyzable GTP analogs. These results suggest that EF-Ts serves an unanticipated role in the cell of actively regulating the abundance and stability of ternary complex in a manner that contributes to rapid and faithful protein synthesis. |
| Databáze: | OpenAIRE |
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