The green alga Scenedesmus pupukensis and the red alga Porphyra spiralis contain large group-IC1 introns in their nuclear small subunit ribosomal RNA genes due to the presence of open reading frames at the 5' end of the introns. The putative 555 amino-acid Scenedesmus-encoded protein harbors a sequence motif resembling the bacterial S9 ribosomal proteins. The Porphyra intron self-splices in vitro, and generates both ligated exons and a full-length intron RNA circle. The Porphyra intron has an unusual structural organization by encoding a potential 149 amino-acid homing-endonuclease-like protein on the complementary strand. A comparison between related group-I introns in the Bangiophyceae revealed homing-endonuclease-like pseudogenes due to frame-shifts and deletions in Porphyra and Bangia. The Scenedesmus and Porphyra introns provide new insights into the evolution and possible novel functions of nuclear group-I intron proteins.
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http://dx.doi.org/10.1007/s002940050509 | DOI Listing |
Naturwissenschaften
January 2025
Department of Biology, University of Washington, Seattle, WA, 98195, USA.
Four main classes of introns (group I, group II, spliceosomal, and archaeal) have been reported for all major types of RNA from nuclei and organelles of a wide range of taxa. When and how introns inserted within the genic regions of genomes, however, is often unclear. Introns were examined from Archaea, Bacteria, and Eukarya.
View Article and Find Full Text PDFInt J Mol Sci
November 2024
School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China.
is an important oil crop in China and has a great demand for nitrogen nutrients. Cationic amino acid transporters (CAT) play a key role in amino acid absorption and transport in plants. However, the family has not been reported in so far.
View Article and Find Full Text PDFCan J Microbiol
December 2024
Department of Microbiology, University of Manitoba, Winnipeg, MB R3T 2N2, Canada.
is a fungal associate of (the pine shoot beetle) and pathogen of pines and this species is an agent of blue stain in sapwood on infected trees. This fungus was first reported from Europe and has been recently introduced to Canadian forests. Ten new mitogenomes have been sequenced and characterized, including seven strains of , two strains of and one strain of .
View Article and Find Full Text PDFRNA Biol
January 2024
McKetta Department of Chemical Engineering, The University of Texas at Austin, Austin, TX, USA.
MedComm (2020)
November 2024
Small molecule drugs are increasingly emerging as innovative and effective treatments for various diseases, with mRNA therapeutics being a notable representative. The success of COVID-19 vaccines has underscored the transformative potential of mRNA in RNA therapeutics. Within the RNA family, there is another unique type known as circRNA.
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