Mitochondrial tRNA gene mutations, including heteroplasmic deletions that eliminate one or more tRNAs, as well as point mutations that may be either hetero- or homoplasmic, are associated with a wide spectrum of human diseases. These range from rare syndromic disorders to cases of commoner conditions such as sensorineural deafness or cardiomyopathy. The disease spectrum of mutations in a given ...

In a patient with refractory anemia with excess blasts (RAEB), a somatic mutation of mitochondrial transfer RNA(Leu(UUR)) was detected in bone marrow cells. Heteroduplex analysis indicated that 40% to 50% of mitochondrial DNA (mtDNA) molecules in the bone marrow (BM) carried the novel G3242A mutation. The proportion of mutant mtDNA was higher in CD34(+) cells than in the unfractionated sample. ...

MTU1 (TRMU) is a mitochondrial enzyme responsible for the 2-thiolation of the wobble U in tRNA(Lys), tRNA(Glu) and tRNA(Gln), a post-transcriptional modification believed to be important for accurate and efficient synthesis of the 13 respiratory chain subunits encoded by mtDNA. Mutations in MTU1 are associated with acute infantile liver failure, and this has been ascribed to a transient lack of...

Abstract Background Mutations in lysyl-tRNA synthetase ( KARS1 ), an enzyme that charges tRNA with the amino acid lysine both cytoplasm and mitochondria, have been associated thus far autosomal recessive Charcot–Marie–Tooth type CMTRIB, hearing loss DFNB89, mitochondrial encephalohepatopathy (MEH) featuring neurodevelopmental disorders microcephaly, white matter changes, cardiac hepatic failure...

BACKGROUND Animal mitochondrial genomes typically encode one tRNA for each synonymous codon family, so that each tRNA anticodon essentially has to wobble to recognize two or four synonymous codons. Several factors have been hypothesized to determine the nucleotide at the wobble site of a tRNA anticodon in mitochondrial genomes, such as the codon-anticodon adaptation hypothesis, the wobble versa...

Maternally inherited diabetes and deafness (MIDD), also called mitochondrial diabetes mellitus, is a rare form of diabetes that comprises 0.5-2.8% of the diabetic population. Most cases of MIDD are associated with a point mutation in the mitochondrial DNA (mtDNA) at position 3243 of the leucine tRNA gene (A3243G) . Patients with MIDD are characterized by 1) young onset of diabetes, 2) absence o...

Saccharomyces cerevisiae strain FF1210-6C/170 is respiratory deficient due to a mutation of the penultimate base of the mitochondrial tRNA(Asp) gene. We have identified a number of progeny from this strain which have reverted to respiratory sufficiency by the excision and tandem amplification of a small region of the mitochondrial (mt) DNA carrying the tRNA(Asp) gene, while also maintaining the...

Mitochondrial aminoacyl-tRNA synthetases (aaRSs) are essential enzymes in protein synthesis since they charge tRNAs with their cognate amino acids. Mutations in the genes encoding mitochondrial aaRSs have been associated with a wide spectrum of human mitochondrial diseases. Here we report the identification of pathogenic mutations (a partial genomic deletion and a highly conserved p. Asp325Tyr ...

Background: Pregnancy is the process from the fertilized ovum to the fetus with capability of extra uterine survival. Pregnancy loss is the most common complication of pregnancies. Advances in the detection of early pregnancy revealed that about 70% of human conceptions fail to achieve viability but clinically recognized pregnancies terminate as a miscarriage in about 15% of cases. About 1 in 3...

The nuclear suppressor allele NSM3 in strain FF1210-6C/170-E22 (E22), which suppresses a mutation of the yeast mitochondrial tRNA(Asp)gene in Saccharomyces cerevisiae, was cloned and identified. To isolate the NSM3 allele, a genomic DNA library using the vector YEp13 was constructed from strain E22. Nine YEp13 recombinant plasmids were isolated and shown to suppress the mutation in the mitochon...