Kinetic Parameters for tmRNA Binding to Alanyl-tRNA Synthetase and Elongation Factor Tu from Escherichia coli
| Autor: | Sharief Barends, Barend Kraal, Jacek Wower |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Transcription
Genetic GTP' Acylation Alanine-tRNA Ligase RNA Transfer Ala Aminoacylation Peptide Elongation Factor Tu Biology medicine.disease_cause Biochemistry Ribosome Kinetics Biopolymers Escherichia coli medicine Thermodynamics RNA Messenger Enzyme kinetics EF-Tu Trans-translation Transfer-messenger RNA |
| Zdroj: | Biochemistry. 39:2652-2658 |
| ISSN: | 1520-4995 0006-2960 |
| Popis: | Aminoacylation and transportation of tmRNA to stalled ribosomes constitute prerequisite steps for trans-translation, a process facilitating the release of stalled ribosomes from 3' ends of truncated mRNAs and the degradation of incompletely synthesized proteins. Kinetic analysis of the aminoacylation of tmRNA indicates that tmRNA has both a lower affinity and a lower turnover number than cognate tRNA(Ala) for alanyl-tRNA synthetase, resulting in a 75-fold lower k(cat)/K(M) value. The association rate constant of Ala-tmRNA for elongation factor Tu in complex with GTP is about 150-fold lower than that of Ala-tRNA(Ala), whereas its dissocation rate constant is about 5-fold lower. These observations can be interpreted to suggest that additional factors facilitate tmRNA binding to ribosomes. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|