The tRNA structure contains conserved modifications that are responsible for its stability and are involved in the initiation and accuracy of the translation process. tRNA modification enzymes are prevalent in bacteria, archaea, and eukaryotes. tRNA Gm18 methyltransferase (TrmH) and tRNA m(1)G37 methyltransferase (TrmD) are prevalent and essential enzymes in bacterial populations. TrmH involves itself in methylation process at the 2'-OH group of ribose at the 18th position of guanosine (G) in tRNAs. TrmD methylates the G residue next to the anticodon in selected tRNA subsets. Initially, m(1)G37 modification was reported to take place on three conserved tRNA subsets (tRNA(Arg), tRNA(Leu), tRNA(Pro)); later on, few archaea and eukaryotes organisms revealed that other tRNAs also have the m(1)G37 modification. The present study reveals Gm18, m(1)G37 modification, and positions of m(1)G that take place next to the anticodon in tRNA sequences. We selected extremophile organisms and attempted to retrieve the m(1)G and Gm18 modification bases in tRNA sequences. Results showed that the Gm18 modification G residue occurs in all tRNA subsets except three tRNAs (tRNA(Met), tRNA(Pro), tRNA(Val)). Whereas the m(1)G37 modification base G is formed only on tRNA(Arg), tRNA(Leu), tRNA(Pro), and tRNA(His), the rest of the tRNAs contain adenine (A) next to the anticodon. Thus, we hypothesize that Gm18 modification and m(1)G modification occur irrespective of a G residue in tRNAs.
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http://dx.doi.org/10.5808/GI.2014.12.2.71 | DOI Listing |
J Zhejiang Univ Sci B
January 2023
Department of Genetics, and Department of Genetic and Metabolic Disease, The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou 310052, China.
Accumulating evidence has confirmed the links between transfer RNA (tRNA) modifications and tumor progression. The present study is the first to explore the role of tRNA methyltransferase 5 (TRMT5), which catalyzes the m1G37 modification of mitochondrial tRNAs in hepatocellular carcinoma (HCC) progression. Here, based on bioinformatics and clinical analyses, we identified that TRMT5 expression was upregulated in HCC, which correlated with poor prognosis.
View Article and Find Full Text PDFCell Rep
October 2022
Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, PA, USA. Electronic address:
Codon usage of each genome is closely correlated with the abundance of tRNA isoacceptors. How codon usage bias is resolved by tRNA post-transcriptional modifications is largely unknown. Here we demonstrate that the N-methylation of guanosine at position 37 (mG37) on the 3'-side of the anticodon, while not directly responsible for reading of codons, is a neutralizer that resolves differential decoding of proline codons.
View Article and Find Full Text PDFNucleic Acids Res
December 2021
Protein Engineering and Evolution Unit, Okinawa Institute of Science and Technology, Onna, Okinawa 904-0495, Japan.
The tRNA modification m1G37, introduced by the tRNA methyltransferase TrmD, is thought to be essential for growth in bacteria because it suppresses translational frameshift errors at proline codons. However, because bacteria can tolerate high levels of mistranslation, it is unclear why loss of m1G37 is not tolerated. Here, we addressed this question through experimental evolution of trmD mutant strains of Escherichia coli.
View Article and Find Full Text PDFBiosystems
August 2021
The Ionian School, Genetic Code and tRNA Origin Laboratory, Via Roma 19, 67030, Alfedena, L'Aquila, Italy; Institute of Biosciences and Bioresources, National Research Council, Via P. Castellino, 111, 80131, Naples, Italy. Electronic address:
I analyzed the implications of the observation that the methyltransferases, Trm5 and TrmD, which perform the methylation of the 37th base (mG37) in tRNAs of bacteria and archaea respectively, are not homologous proteins. The first implication is that these methyltransferases originated very late only when the fundamental lineages leading to bacteria and archaea had separated, otherwise the two methyltransferases would have been homologous enzymes, which they are not. The conclusion that Trm5 and TrmD originated only when the main lineages were defined would imply that at least some aspects of the translation, such as +1 frameshifting, were still in rapid and progressive evolution, that is, they were still originating.
View Article and Find Full Text PDFNucleic Acids Res
January 2021
Division of Medical Genetics and Genomics, The Children's Hospital, Zhejiang University School of Medicine and National Clinical Research Center for Child Health, Hangzhou, Zhejiang 310058, China.
Defects in the posttranscriptional modifications of mitochondrial tRNAs have been linked to human diseases, but their pathophysiology remains elusive. In this report, we investigated the molecular mechanism underlying a deafness-associated tRNAIle 4295A>G mutation affecting a highly conserved adenosine at position 37, 3' adjacent to the tRNA's anticodon. Primer extension and methylation activity assays revealed that the m.
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