Send to

Choose Destination
See comment in PubMed Commons below
Biochemistry. 2000 Mar 14;39(10):2652-8.

Kinetic parameters for tmRNA binding to alanyl-tRNA synthetase and elongation factor Tu from Escherichia coli.

Author information

  • 1Department of Biochemistry, Leiden Institute of Chemistry, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands.


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.

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for American Chemical Society
    Loading ...
    Support Center