The Role of Cysteinyl Residues in the Activity of Bacterial Elongation Factor Ts, a Guanosine Nucleotide Dissociation Protein
| Autor: | Yu-Wen Hwang, David Miller, Anthony Sanchez, Mo-Chou Chen Hwang |
|---|---|
| Rok vydání: | 1997 |
| Předmět: |
Protein Conformation
Stereochemistry Glycine Biophysics Guanosine Guanosine Diphosphate Biochemistry Serine chemistry.chemical_compound Protein structure Escherichia coli Native state Protein biosynthesis Cysteine Cloning Molecular Molecular Biology Sequence Tagged Sites Chemistry Peptide Elongation Factors Recombinant Proteins Kinetics Amino Acid Substitution Catalytic cycle Mutagenesis Site-Directed EF-Tu |
| Zdroj: | Archives of Biochemistry and Biophysics. 348:157-162 |
| ISSN: | 0003-9861 |
| DOI: | 10.1006/abbi.1997.0375 |
| Popis: | The modification of E.coli elongation factor Ts (EF-Ts) by NEM and other sulfhydryl reagents inactivates the protein's ability to bind EF-Tu.GDP and to catalyze GDP exchange. The reactive residue was found to be Cys-22. Replacement of Cys-22 by Ser or Gly only partially impairs the binding or catalytic properties of EF-Ts while it completely protects EF-Ts from the inactivation by NEM. Cys-22 of EF-Ts is not located at the EF-Ts.EF-Tu interface, yet it can be modified only when EF-Ts is not bound to EF-Tu. These results support the proposal that the conformation change around Cys-22 in the amino terminus of EF-Ts rather than Cys-22 itself is essential for binding EF-Tu. Apparently, modification of Cys-22 by NEM disrupts the conformation change and inactivates EF-Ts. The return of EF-Ts to its native conformation may provide the driving force for the rate-determining step in the catalytic cycle, the dissociation of EF-Ts from EF-Tu.GNP. |
| Databáze: | OpenAIRE |
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