Soybean seedlings were examined for the presence of mitochondrial tRNA. Tyrosyl transfer tRNAs from whole cells, from a well characterized mitochondrial preparation, and from a snake venom phosphodiesterase-treated mitochondrial preparation, were compared by reverse phase chromatography. It was concluded that none of the three previously reported tRNA(Tyr) species were mitochondrial. Rather, a ...

Three tRNA genes have been isolated from a genomic library of Arabidopsis thaliana: a tRNA (GCU), a tRNA (GUA) and a tRNA (UUC) genes. These genes are located closely on the same DNA fragment. The tRNA and the tRNA genes have both 99% sequence similarity with their mitochondrial counterparts from higher plants indicating that these three tRNA genes are mitochondrial. The tRNAv gene shows a part...

Editing is a general event in plant mitochondrial messenger RNAs, but has never been detected in a plant mitochondrial transfer RNA (tRNA). We demonstrate here the occurrence of a tRNA editing event in higher plant mitochondria: in both bean and potato, the C encoded at position 4 in the mitochondrial tRNA(Phe)(GAA) gene is converted into a U in the mature tRNA. This nucleotide change corrects ...

introduction: a number of maternally inherited mitochondrial diseases with distinct clinical phenotypes have been associated with point mutations in mtdna, all of which result in neurologic or neuromuscular disorders. several studies showed that mutations in the trna genes of mtdna could cause mitochondrial disease due to the decreased synthesis of mitochondrial dna coded proteins. materials an...

Total transfer RNAs were extracted from highly purified potato mitochondria. From quantitative measurements, the in vivo tRNA concentration in mitochondria was estimated to be in the range of 60 microM. Total potato mitochondrial tRNAs were fractionated by two-dimensional polyacrylamide gel electrophoresis. Thirty one individual tRNAs, which could read all sense codons, were identified by amino...

By two-dimensional polyacrylamide gel electrophoresis, yeast mitochondrial tRNA is fractionated into 27 major species. All but 6 of them migrate distinctly from cytoplasmic tRNAs. Migration of mitochondrial DNA-coded mitochondrial tRNAs shows the occurence of only one cytoplasmic tRNA in mitochondria. Several mitochondrial tRNA spots are identified on the electrophoregrams, some of them show is...

All mitochondrial tRNAs in Leishmania tarentolae are encoded in the nuclear genome and imported into the mitochondrion from the cytosol. One imported tRNA (tRNA(Trp)) is edited by a C to U modification at the first position of the anticodon. To determine the in vivo substrates for mitochondrial tRNA importation as well as tRNA editing, we examined the subcellular localization and extent of 5'- ...

Mutations in mitochondrial tRNA genes are associated with a wide spectrum of human diseases. In particular, the tRNA(Leu(UUR)) A3243G mutation causes mitochondrial encephalomyopathy, lactic acidosis, and stroke-like symptoms (MELAS) and 2% of cases of type 2 diabetes. The primary defect in this mutation was an inefficient aminoacylation of the tRNA(Leu(UUR)). In the present study, we have inves...

The metazoan mitochondrial translation machinery is unusual in having a single tRNA(Met) that fulfills the dual role of the initiator and elongator tRNA(Met). A portion of the Met-tRNA(Met) pool is formylated by mitochondrial methionyl-tRNA formyltransferase (MTFMT) to generate N-formylmethionine-tRNA(Met) (fMet-tRNA(met)), which is used for translation initiation; however, the requirement of f...

Aminoacyl tRNA synthetases play a central role in protein synthesis by charging tRNAs with amino acids. Yeast mitochondrial lysyl tRNA synthetase (Msk1), in addition to the aminoacylation of mitochondrial tRNA, also functions as a chaperone to facilitate the import of cytosolic lysyl tRNA. In this report, we show that human mitochondrial Kars (lysyl tRNA synthetase) can complement the growth de...