Nucleic Acids Research Advance Access originally published online on May 3, 2007
Nucleic Acids Research 2007 35(10):3420-3430; doi:10.1093/nar/gkm211
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Nucleic Acids Research, 2007, Vol. 35, No. 10 3420-3430
© 2007 The Author(s)
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/2.0/uk/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
Molecular Biology |
Structural elements defining elongation factor Tu mediated suppression of codon ambiguity
UPR 9002, ‘Architecture et Réactivité de l’ARN’, Institut de Biologie Moléculaire et Cellulaire du CNRS, 15, Rue René Descartes and Université Louis Pasteur, F-67084 Strasbourg Cédex, France
*To whom correspondence should be addressed. Tel: +33-3-8841-7092; Fax: +33-3-8860-2218; Email: d.kern{at}ibmc.u-strasbg.fr
Received January 23, 2007. Revised March 24, 2007. Accepted March 27, 2007.
In most prokaryotes Asn-tRNAAsn and Gln-tRNAGln are formed by amidation of aspartate and glutamate mischarged onto tRNAAsn and tRNAGln, respectively. Coexistence in the organism of mischarged Asp-tRNAAsn and Glu-tRNAGln and the homologous Asn-tRNAAsn and Gln-tRNAGln does not, however, lead to erroneous incorporation of Asp and Glu into proteins, since EF-Tu discriminates the misacylated tRNAs from the correctly charged ones. This property contrasts with the canonical function of EF-Tu, which is to non-specifically bind the homologous aa-tRNAs, as well as heterologous species formed in vitro by aminoacylation of non-cognate tRNAs. In Thermus thermophilus that forms the Asp-tRNAAsn intermediate by the indirect pathway of tRNA asparaginylation, EF-Tu must discriminate the mischarged aminoacyl-tRNAs (aa-tRNA). We show that two base pairs in the tRNA T-arm and a single residue in the amino acid binding pocket of EF-Tu promote discrimination of Asp-tRNAAsn from Asn-tRNAAsn and Asp-tRNAAsp by the protein. Our analysis suggests that these structural elements might also contribute to rejection of other mischarged aa-tRNAs formed in vivo that are not involved in peptide elongation. Additionally, these structural features might be involved in maintaining a delicate balance of weak and strong binding affinities between EF-Tu and the amino acid and tRNA moieties of other elongator aa-tRNAs.
Present address: Hervé Roy, Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  K. Sheppard, J. Yuan, M. J. Hohn, B. Jester, K. M. Devine, and D. Soll From one amino acid to another: tRNA-dependent amino acid biosynthesis Nucleic Acids Res., April 1, 2008; 36(6): 1813 - 1825. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Ling, S. S. Yadavalli, and M. Ibba Phenylalanyl-tRNA synthetase editing defects result in efficient mistranslation of phenylalanine codons as tyrosine RNA, November 1, 2007; 13(11): 1881 - 1886. [Abstract] [Full Text] [PDF]
|
|