Nucleic Acids Research, 1994, Vol. 22, No. 18 3699-3705
© 1994
RNA |
Nuclear-encoded mitochondrial tRNAs of Trypanosoma brucei have a modified cytidine in the anticodon loop
Intercampus Program in Molecular Parasitology, Laurel Heights Campus, University of California San Francisco and Berkeley, San Francisco, CA 94143-1204, USA
*To whom correspondence should be addressed
Received June 9, 1994. Revised August 10, 1994. Accepted August 10, 1994.
The mitochondrial genome of Trypanosoma brucei does not appear to encode any tRNA genes. Isolated organellar tRNAs hybridize to nuclear DNA, suggesting that they are synthesized in the nucleus and subsequently imported into the mitochondrion. Most imported tRNAs have cytosolic counterparts, showing identical mobility on two-dimensional polyacrylamide gels. We have compared three nuclear-encoded mitochondrial tRNAs (tRNALys, tRNALeu, tRNATyr) with their cytosolic isoforms by direct enzymatic sequence analysis. Our findings indicate that the primary sequences of the mitochondrial and the corresponding cytosolic tRNAs are identical. However, we have identified a mitochondrion-specific nucleotide modification of each tRNA which is localized to a conserved cytidine residue at the penultimate position 5' of the anticodon. The modification present in mature mitochondrial tRNATyr was not found in a mutant tRNATyr defective in splicing in either cytosolic or mitochondrial fractions. The mutant tRNATyr has been expressed in transformed cells and its import into mitochondria has been demonstrated, suggesting that the modified cytidine residue is not required for import and therefore may be involved in adapting imported tRNAs to specific requirements of the mitochondrial translation machinery.
$Present address: Biozentrum, University of Basel, Department of Biochemistry, Klingelbergstrasse 70, CH-4056 Basel, Switzerland
![]()
CiteULike
Connotea
Del.icio.us What's this?
This article has been cited by other articles:
![]() |
N. Shigi, T. Suzuki, T. Terada, M. Shirouzu, S. Yokoyama, and K. Watanabe Temperature-dependent Biosynthesis of 2-Thioribothymidine of Thermus thermophilus tRNA J. Biol. Chem., January 27, 2006; 281(4): 2104 - 2113. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Crausaz Esseiva, L. Marechal-Drouard, A. Cosset, and A. Schneider The T-Stem Determines the Cytosolic or Mitochondrial Localization of Trypanosomal tRNAsMet Mol. Biol. Cell, June 1, 2004; 15(6): 2750 - 2757. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. F. Agris Decoding the genome: a modified view Nucleic Acids Res., January 9, 2004; 32(1): 223 - 238. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. H. P. Tan, R. Pach, A. Crausaz, A. Ivens, and A. Schneider tRNAs in Trypanosoma brucei: Genomic Organization, Expression, and Mitochondrial Import Mol. Cell. Biol., June 1, 2002; 22(11): 3707 - 3717. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. E. Nabholz, E. K. Horn, and A. Schneider tRNAs and Proteins Are Imported into Mitochondria of Trypanosoma brucei by Two Distinct Mechanisms Mol. Biol. Cell, August 1, 1999; 10(8): 2547 - 2557. [Abstract] [Full Text] |
||||
![]() |
A. J. LeBlanc, A. E. Yermovsky-Kammerer, and S. L. Hajduk A Nuclear Encoded and Mitochondrial Imported Dicistronic tRNA Precursor in Trypanosoma brucei J. Biol. Chem., July 23, 1999; 274(30): 21071 - 21077. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. T. Beagley, R. Okimoto, and D. R. Wolstenholme The Mitochondrial Genome of the Sea Anemone Metridium senile (Cnidaria): Introns, a Paucity of tRNA Genes, and a Near-Standard Genetic Code Genetics, March 1, 1998; 148(3): 1091 - 1108. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. T. Kapushoc, J. D. Alfonzo, M. A. T. Rubio, and L. Simpson End Processing Precedes Mitochondrial Importation and Editing of tRNAs in Leishmania tarentolae J. Biol. Chem., November 22, 2000; 275(48): 37907 - 37914. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. H. P. Tan, N. Bochud-Allemann, E. K. Horn, and A. Schneider Eukaryotic-type elongator tRNAMet of Trypanosoma brucei becomes formylated after import into mitochondria PNAS, February 5, 2002; 99(3): 1152 - 1157. [Abstract] [Full Text] [PDF] |
||||





