Protein-disulfide isomerase activity of elongation factor EF-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 and others have recently shown that the Escherichia coli EF-Tu, in additon to its acknowledged role in translation elongation, displays chaperone-like properties. We report here that EF-Tu, like thioredoxin, protein disulfide isomerase, and DsbA, catalyzes protein disulfide formation (oxidative renaturation of reduced RNase), reduction (reduction of insulin disulfides), and isomerization (refolding of randomly oxidized RNase). In contrast with most protein disulfide isomerases which possess vicinal cysteines and form an intramolecular disulfide upon oxidation, EF-Tu, which does not possess vicinal cysteines, forms intermolecular disulfides upon oxidation, resulting in the appearance of multimeric forms.
Richarme
G
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Biochimie Génétique, Institut Jacques Monod, Université Paris 7, 2 Place Jussieu, Paris Cedex 05, 75251, France. richarme@ccr.jussieu.fr
D002384:Catalysis; D004229:Dithiothreitol / Q000494:pharmacology; D004926:Escherichia coli / Q000378:metabolism*; D006153:Guanosine Diphosphate / Q000378:metabolism; D007328:Insulin / Q000378:metabolism; D007700:Kinetics; D010084:Oxidation-Reduction; D010444:Peptide Elongation Factor Tu / Q000302:isolation & purification / Q000378:metabolism*; D019704:Protein Disulfide-Isomerases / Q000378:metabolism*; D017510:Protein Folding; D012260:Ribonucleases / Q000378:metabolism; D013879:Thioredoxins / Q000378:metabolism
D007328:Insulin; D006153:Guanosine Diphosphate; D013879:Thioredoxins; D012260:Ribonucleases; D010444:Peptide Elongation Factor Tu; D019704:Protein Disulfide-Isomerases; D004229:Dithiothreitol