Catherine Florentz

Learn More
About 2000 completely sequenced mitochondrial genomes are available from the NCBI RefSeq data base together with manually curated annotations of their protein-coding genes, rRNAs, and tRNAs. This annotation information, which has accumulated over two decades, has been obtained with a diverse set of computational tools and annotation strategies. Despite all(More)
Transfer RNAs (tRNAs) are present in all types of cells as well as in organelles. tRNAs of animal mitochondria show a low level of primary sequence conservation and exhibit 'bizarre' secondary structures, lacking complete domains of the common cloverleaf. Such sequences are hard to detect and hence frequently missed in computational analyses and(More)
A growing number of mutated mitochondrial tRNA genes have been found associated with severe human diseases. To investigate the potential interference of such mutations with the primordial function of tRNAs, i.e. their aminoacylation by cognate aminoacyl-tRNA synthetases, a human mitochondrial in vitro aminoacylation system specific for isoleucine has been(More)
The molecular recognition of specific transfer RNAs by the appropriate aminoacyl-tRNA synthetase is an important step in determining the accuracy of translation of the genetic message from nucleic acids into proteins. Recent studies using variant tRNAs with specific sequence modifications have indicated particular regions that determine their identity. Here(More)
Here we demonstrate association of variants in the mitochondrial asparaginyl-tRNA synthetase NARS2 with human hearing loss and Leigh syndrome. A homozygous missense mutation ([c.637G>T; p.Val213Phe]) is the underlying cause of nonsyndromic hearing loss (DFNB94) and compound heterozygous mutations ([c.969T>A; p.Tyr323*] + [c.1142A>G; p.Asn381Ser]) result in(More)
The mitochondrial genome of metazoan animal typically encodes 22 tRNAs. Nematode mt-tRNAs normally lack the T-stem and instead feature a replacement loop. In the class Enoplea, putative mt-tRNAs that are even further reduced have been predicted to lack both the T- and the D-arm. Here we investigate these tRNA candidates in detail. Three lines of(More)
The human mitochondrial genome encodes 22 tRNAs interspersed among the two rRNAs and 11 mRNAs, often without spacers, suggesting that tRNAs must be efficiently excised. Numerous maternally transmitted diseases and syndromes arise from mutations in mitochondrial tRNAs, likely due to defect(s) in tRNA metabolism. We have systematically explored the effect of(More)
BACKGROUND Mitochondrial DNA (mtDNA) diseases are rare disorders whose prevalence is estimated around 1 in 5000. Patients are usually tested only for deletions and for common mutations of mtDNA which account for 5-40% of cases, depending on the study. However, the prevalence of rare mtDNA mutations is not known. METHODS We analysed the whole mtDNA in a(More)
The nucleotides crucial for the specific aminoacylation of yeast tRNA(Asp) by its cognate synthetase have been identified. Steady-state aminoacylation kinetics of unmodified tRNA transcripts indicate that G34, U35, C36, and G73 are important determinants of tRNA(Asp) identity. Mutations at these positions result in a large decrease (19- to 530-fold) of the(More)
Mutations have been designed that disrupt the tertiary structure of yeast tRNA(Asp). The effects of these mutations on both tRNA structure and specific aspartylation by yeast aspartyl-tRNA synthetase were assayed. Mutations that disrupt tertiary interactions involving the D-stem or D-loop result in destabilization of the base-pairing in the D-stem, as(More)