Abstract
Elongation factor Tu (EF-Tu) is involved in the binding and transport of the appropriate codon-specified aminoacyl-tRNA to the aminoacyl site of the ribosome. We report herewith that the Escherichia coli EF-Tu interacts with unfolded and denatured proteins as do molecular chaperones that are involved in protein folding and protein renaturation after stress. EF-Tu promotes the functional folding of citrate synthase and alpha-glucosidase after urea denaturation. It prevents the aggregation of citrate synthase under heat shock conditions, and it forms stable complexes with several unfolded proteins such as reduced carboxymethyl alpha-lactalbumin and unfolded bovine pancreatic trypsin inhibitor. The EF-Tu.GDP complex is much more active than EF-Tu.GTP in stimulating protein renaturation. These chaperone-like functions of EF-Tu occur at concentrations that are at least 20-fold lower than the cellular concentration of this factor. These results suggest that EF-Tu, in addition to its function in translation elongation, might be implicated in protein folding and protection from stress.
Highlights
EF-Tu1 is responsible for binding and transporting the appropriate codon-specified aminoacyl-tRNA to the aminoacyl (A) site of the ribosome [1, 2]
We show that elongation factor Elongation factor Tu (EF-Tu), in a manner similar to that of molecular chaperones, increases the refolding of unfolded proteins, protects proteins against thermal denaturation, and forms complexes with unfolded proteins
EF-Tu Increases the Amount of Correctly Folded Citrate Synthase and ␣-Glucosidase—We first investigated whether EF-Tu acts as molecular chaperones in the folding of proteins
Summary
EF-Tu1 is responsible for binding and transporting the appropriate codon-specified aminoacyl-tRNA to the aminoacyl (A) site of the ribosome [1, 2]. We show that elongation factor EF-Tu, in a manner similar to that of molecular chaperones, increases the refolding of unfolded proteins, protects proteins against thermal denaturation, and forms complexes with unfolded proteins. Preparation of EF-Tu1⁄7GDP and EF-Tu1⁄7GTP—EF-Tu1⁄7GDP was formed by incubating EF-Tu (1–10 M) in the presence of 20 M GDP in citrate synthase or ␣-glucosidase renaturation buffers supplemented with 200 M MgCl2.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
