Nucleic Acids Research, Vol 26, Issue 6 1390-1395, Copyright © 1998 by Oxford University Press
M Baum and H Beier
Many RNA viruses express part of their genomic information by read- through
over internal termination codons. We have recently characterized tobacco
cytoplasmic (cyt) and chloroplast (chl) tRNACmCATrp and tRNAGCACys as
natural suppressor tRNAs that are able to read the leaky UGA codon in RNA-1
of tobacco rattle virus, albeit with different efficiencies. Here we have
identified a third natural UGA suppressor in plants. We have purified and
sequenced four cyt tRNAArg isoacceptors with ICG, CCG, U*CG and CCU
anticodons from wheat germ. With the exception of tRNAICGArg, these are the
first sequences of plant tRNAsArg. In order to study the potential
suppressor activity of wheat tRNAsArg we have used in vitro synthesized
mRNA transcripts in which different viral read-through regions had been
placed. In vitro translation was carried out in a homologous wheat germ
extract. We found that tRNAU*CGArg is an efficient UGA suppressor in vitro,
whereas the other three tRNAArg isoacceptors exhibit no or very low
suppressor activity. Interaction of tRNAU*CGArg with the UGA codon requires
a G:U base pair at the third anticodon position. This is the first time
that an arginine-accepting tRNA has been characterized as a natural UGA
suppressor. A remarkable feature of cyt tRNAU*CGArg is its ability to
misread the UGA at the end of the coat protein cistron in RNA-1 of pea
enation mosaic virus, which is not accomplished by cyt tRNACmCATrp or cyt
tRNAGCACys, due to an unfavourable codon context.
ARTICLES
Wheat cytoplasmic arginine tRNA isoacceptor with a U*CG anticodon is an efficient UGA suppressor in vitro
Institut fur Biochemie, Bayerische Julius-Maximilians-Universitat, Biozentrum, Am Hubland, D-97074 Wurzburg, Germany. baum@biozentrum.uni- wuerzburg.de
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  H. Beier and M. Grimm Misreading of termination codons in eukaryotes by natural nonsense suppressor tRNAs Nucleic Acids Res., December 1, 2001; 29(23): 4767 - 4782. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 G. Bertram, S. Innes, O. Minella, J. P. Richardson, and I. Stansfield Endless possibilities: translation termination and stop codon recognition Microbiology, February 1, 2001; 147(2): 255 - 269. [Full Text]
|
|
|
|
 |
|
 Z. Wang, A. Gaba, and M. S. Sachs A Highly Conserved Mechanism of Regulated Ribosome Stalling Mediated by Fungal Arginine Attenuator Peptides That Appears Independent of the Charging Status of Arginyl-tRNAs J. Biol. Chem., December 31, 1999; 274(53): 37565 - 37574. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. E. Glover, D. F. Spencer, and M. W. Gray Identification and Structural Characterization of Nucleus-encoded Transfer RNAs Imported into Wheat Mitochondria J. Biol. Chem., January 5, 2001; 276(1): 639 - 648. [Abstract] [Full Text] [PDF]
|
|