Introns are found in various tRNA genes in all the three kingdoms of life. Especially, archaeal and eukaryotic genomes are good sources of tRNA introns that are removed by proteinaceous splicing machinery. Most intron-containing tRNA genes both in archaea and eukaryotes possess an intron at a so-called canonical position, one nucleotide 3' to their anticodon, while recent bioinformatics have revealed unusual types of tRNA introns and their derivatives especially in archaeal genomes. Gain and loss of tRNA introns during various stages of evolution are obvious both in archaea and eukaryotes from analyses of comparative genomics. The splicing of tRNA molecules has been studied extensively from biochemical and cell biological points of view, and such analyses of eukaryotic systems provided interesting findings in the past years. Here, I summarize recent progresses in the analyses of tRNA introns and the splicing process, and try to clarify new and old questions to be solved in the next stages.
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http://dx.doi.org/10.3389/fgene.2014.00213 | DOI Listing |
Front Plant Sci
December 2024
National Institute of Molecular Biology and Biotechnology, College of Science, University of the Philippines Diliman, Quezon City, Philippines.
Transfer RNAs (tRNAs) are noncoding RNAs involved in protein biosynthesis and have noncanonical roles in cellular metabolism, such as RNA silencing and the generation of transposable elements. Extensive tRNA gene duplications, modifications to mature tRNAs, and complex secondary and tertiary structures impede tRNA sequencing. As such, a comparative genomic analysis of complete tRNA sets is an alternative to understanding the evolutionary processes that gave rise to the extant tRNA sets.
View Article and Find Full Text PDFFungal Genet Biol
January 2025
Conway Institute and School of Medicine, University College Dublin, Dublin 4, Ireland. Electronic address:
Zymocin-like killer toxins are anticodon nucleases secreted by some budding yeast species, which kill competitor yeasts by cleaving tRNA molecules. They are encoded by virus-like elements (VLEs), cytosolic linear DNA molecules that are also called killer plasmids. To date, toxins of this type have been found only in budding yeast species (Saccharomycotina).
View Article and Find Full Text PDFMob DNA
January 2025
Department of Biology, La Sierra University, Riverside, CA, USA.
Background: Messenger RNA 3' untranslated regions (3'UTRs) control many aspects of gene expression and determine where the transcript will terminate. The polyadenylation signal (PAS) AAUAAA (AATAAA in DNA) is a key regulator of transcript termination and this hexamer, or a similar sequence, is very frequently found within 30 bp of 3'UTR ends. Short interspersed element (SINE) retrotransposons are found throughout genomes in high copy numbers.
View Article and Find Full Text PDFChembiochem
December 2024
University of Palermo: Universita degli Studi di Palermo, STEBICEF, Viale delle Scienze, ed.17, 90128, Palermo, ITALY.
The most recurrent familial cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) is the presence of an abnormal number of intronic GGGGCC (G4C2) repetitions in the C9orf72 gene, which has been proposed to drive ALS/FTD pathogenesis. Recently, it has been shown that such G4C2 repetitions can fold into G-quadruplex (G4) secondary structures. These G4s have been selectively stabilized by small-molecule binders, furnishing proof of principle that targeting these non-canonical nucleic acid sequences represents a novel and effective therapeutic strategy to tackle neurodegenerative disorders.
View Article and Find Full Text PDFMitochondrial DNA B Resour
November 2024
Key Laboratory for Coastal Marine Eco-Environment Process and Carbon Sink of Hainan province, Yazhou Bay Innovation Institute, College of Ecology and Environment, Hainan Tropical Ocean University, Sanya, China.
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