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Synthesis and investigation of the 5-formylcytidine modified, anticodon stem and loop of the human mitochondrial tRNAMet.

ABSTRACT: Human mitochondrial methionine transfer RNA (hmtRNA(Met)(CAU)) has a unique post-transcriptional modification, 5-formylcytidine, at the wobble position-34 (f(5)C(34)). The role of this modification in (hmtRNA(Met)(CAU)) for the decoding of AUA, as well as AUG, in both the peptidyl- and aminoacyl-sites of the ribosome in either chain initiation or chain elongation is still unknown. We report the first synthesis and analyses of the tRNA's anticodon stem and loop domain containing the 5-formylcytidine modification. The modification contributes to the tRNA's anticodon domain structure, thermodynamic properties and its ability to bind codons AUA and AUG in translational initiation and elongation.

SUBMITTER: Lusic H

PROVIDER: S-EPMC2582600 | biostudies-literature | 2008 Nov

REPOSITORIES: biostudies-literature

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Synthesis and investigation of the 5-formylcytidine modified, anticodon stem and loop of the human mitochondrial tRNAMet.

Lusic Hrvoje H Gustilo Estella M EM Vendeix Franck A P FA Kaiser Rob R Delaney Michael O MO Graham William D WD Moye Virginia A VA Cantara William A WA Agris Paul F PF Deiters Alexander A

Nucleic acids research 20081016 20

Human mitochondrial methionine transfer RNA (hmtRNA(Met)(CAU)) has a unique post-transcriptional modification, 5-formylcytidine, at the wobble position-34 (f(5)C(34)). The role of this modification in (hmtRNA(Met)(CAU)) for the decoding of AUA, as well as AUG, in both the peptidyl- and aminoacyl-sites of the ribosome in either chain initiation or chain elongation is still unknown. We report the first synthesis and analyses of the tRNA's anticodon stem and loop domain containing the 5-formylcytid ...[more]

PMID: 18927116

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| S-EPMC145695 | biostudies-other

Human SAMD9 is a Virus-Activatable Anticodon Nuclease Inhibiting Codon-Specific Protein Synthesis

Project description:Transfer RNAs (tRNAs) are one of the most conserved components of protein synthesis machinery. An effective strategy for microbes to defend against viruses or competitors is to employ anticodon nucleases (ACNases) to deplete essential tRNAs and thereby shut off global protein synthesis, but this strategy has not been observed in multicellular eukaryotes. Here, we report that human SAMD9 is a virus-activatable ACNase that specifically depletes phenylalanine tRNA (tRNAPhe), causing codon-specific ribosomal pausing and inducing stress signaling. SAMD9 ACNase can be activated by poxvirus infection or by SAMD9 mutations associated with a spectrum of developmental or immunological disorders, implicating tRNAPhe deficiency as a major toxic effect in these human diseases and suggesting a new therapeutic strategy. The specificity of the ACNase, located to an N-terminal effector domain of SAMD9, is largely determined by a eukaryotic tRNAPhe specific 2’-O-methylation at the wobble position, making eukaryotic tRNAPhe a universal but specific target for SAMD9. The SAMD9 ACNase differs from the microbial ACNases in structure and substrate specificity, suggesting convergent evolution resulted in a universal immune defense strategy targeting tRNAs.

2023-06-07 | GSE230043 | GEO

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