True Mitochondrial tRNA Punctuation and Initiation Using Overlapping Stop and Start Codons at Specific and Conserved Positions - Archive ouverte HAL Accéder directement au contenu
Chapitre D'ouvrage Année : 2018

True Mitochondrial tRNA Punctuation and Initiation Using Overlapping Stop and Start Codons at Specific and Conserved Positions

Eric Faure
  • Fonction : Auteur
  • PersonId : 973746

Résumé

In all the taxa and genomic systems, numerous trn genes (specifying tRNA) exhibit at specific conserved positions nucleotide triplets corresponding to stop codons (TAG/TAA). Similarly, relatively high frequencies of start codons (ATG/ATA) occur in fungi/metazoan mitochondrial-trn genes. The last nucleotide of these triplets is the first involved in the 5′-Dor 5′-T-stem, respectively. Their frequencies are tRNA species dependent. The products of these genes which bear one or two types of these codons are called ss-tRNAs (for stop/start). Metazoan mt-genomes are generally very compact, and many same strand overlapping sequences may simultaneously code for tRNAs and mRNAs. However, this study suggests that overlaps are not a direct mechanism to substantially reduce genome size. For proteinencoding genes, occulting possible overlaps, there are only alternative start codons and/or truncated stop codons, but the first putative in-frame standard initiation codon or complete stop codon is in the upstream or downstream overlapping ss-trn sequences, respectively. Even if, to date, experimental data are missing, stress signals might regulate producing extended or not proteins. Finally, possible implications of tRNA/mRNA hybrid molecules in the “RNA world” to “RNA/protein world” transition will be discussed
Fichier non déposé

Dates et versions

hal-02009615 , version 1 (06-02-2019)

Identifiants

  • HAL Id : hal-02009615 , version 1

Citer

Eric Faure, Roxane Barthelemy. True Mitochondrial tRNA Punctuation and Initiation Using Overlapping Stop and Start Codons at Specific and Conserved Positions. IntechOpen, 2018, Mitochondrial DNA - New insights. ⟨hal-02009615⟩
47 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More