Mitochondrial genomes of lycophytes are surprisingly diverse, including strikingly different transfer RNA (tRNA) gene complements: No mitochondrial tRNA genes are present in the spikemoss Selaginella moellendorffii, whereas 26 tRNAs are encoded in the chondrome of the clubmoss Huperzia squarrosa. Reinvestigating the latter we found that trnL(gag) and trnS(gga) had never before been identified i...

In the mitochondrial genome of the hemichordate Balanoglossus carnosus, the codon AAA, which is assigned to lysine in most metazoans but to asparagine in echinoderms, is absent. Furthermore, the lysine tRNA gene carries an anticodon substitution that renders its gene product unable to decode AAA codons, whereas the asparagine tRNA gene has not changed to encode a tRNA with the ability to recogn...

Two cDNAs encoding human lysyl-tRNA synthetase have been identified. One encodes the cytoplasmic form of the enzyme identified previously. The second cDNA contains the same sequence but with a 180-bp insertion at the 5'-end of the mRNA. This results in a predicted protein whose carboxyl 576 amino acids are identical to those of the cytoplasmic enzyme but with a different amino terminus of 49 am...

Trypanosoma brucei imports all mitochondrial transfer RNAs (tRNAs) from the cytosol. By using cell lines that allow independent tetracycline-inducible RNA interference and isopropyl-β-D-thiogalactopyranoside-inducible expression of a tagged tRNA, we show that ablation of Tim17 and mitochondrial heat-shock protein 70, components of the inner-membrane protein translocation machinery, strongly inh...

Proteins encoded by mitochondrial DNA are translated using mitochondrially encoded tRNAs and rRNAs. As with nuclear encoded tRNAs, mitochondrial tRNAs must be processed to become fully functional. The mitochondrial form of ribonuclease P (mt:RNase P) is responsible for 5'-end maturation and is comprised of three proteins; mitochondrial RNase P protein (MRPP) 1 and 2 together with proteinaceous ...

The complete mitochondrial genome of Chirolophis wui (Wang and Wang, 1935) was sequenced using the Illumina platform. sequence is 16,522 bp in length with 54% A+T content contains 13 protein coding genes (PCGs), 22 transfer RNA (tRNAs), 2 ribosomal (rRNAs), 1 control region (D-loop). H-strand 28 (12 PCGs, 14 tRNAs, rRNAs), whereas L-strand accommodates 9 (ND6 8 tRNAs). nucleotide composition C....

Human mitochondrial ribosomes are highly divergent from all other known ribosomes and are specialized to exclusively translate membrane proteins. They are linked with hereditary mitochondrial diseases and are often the unintended targets of various clinically useful antibiotics. Using single-particle cryogenic electron microscopy, we have determined the structure of its large subunit to 3.4 ang...

Novel or rare variants in mitochondrial tRNA sequences may be observed after mitochondrial DNA analysis. Determining whether these variants are pathogenic is critical, but confirmation of the effect of a variant on mitochondrial function can be challenging. We have used available databases of benign and pathogenic variants, alignment between diverse tRNAs, structural information and comparative...

Amino acid assignments of metazoan mitochondrial codons AGA/AGG are known to vary among animal species; arginine in Cnidaria, serine in invertebrates and stop in vertebrates. We recently found that in the mitochondria of the ascidian Halocynthia roretzi these codons are exceptionally used for glycine, and postulated that they are probably decoded by a tRNA(UCU). In order to verify this notion u...