| Title | The Sua5 protein is essential for normal translational regulation in yeast. | | Author(s) | Lin CA, Ellis SR, True HL | | Institution | Department of Cell Biology and Physiology, Washington University School of Medicine, Department of Biochemistry and Molecular Biology, University of Louisville School of Medicine, Louisville, KY 40292, USA. | | Source | Mol Cell Biol 2009 Nov 2. | | Abstract | The anticodon stem loop of tRNAs requires extensive post-transcriptional modifications in order to maintain structure and stabilize the codon:anticodon interaction. These modifications also play a role in accommodating wobble, allowing a limited pool of tRNAs to recognize degenerate codons. Of particular interest is the formation of a threonylcarbamoyl group on adenosine 37 (t(6)A37) of tRNAs that recognize ANN codons. Located adjacent and 3' to the anticodon, t(6)A37 is a conserved modification that is critical for reading frame maintenance. Recently, the highly conserved YrdC/Sua5 family of proteins was shown to be required for the formation of t(6)A37. Sua5 was originally identified in a screen by virtue of its ability to affect expression from an aberrant upstream AUG in the cyc1 transcript. Together, these findings implicate Sua5 in protein translation at the level of codon recognition. Here, we show that Sua5 is critical for normal translation. The loss of SUA5 causes increased leaky scanning through AUG codons, +1 frameshifting, and nonsense suppression. In addition, the loss of SUA5 amplifies the 20S RNA virus found in Saccharomyces cerevisiae, possibly through an internal ribosome entry site (IRES)-mediated mechanism. This study reveals a critical role for Sua5 and the t(6)A37 modification in translational fidelity. | | Language | ENG | | Pub Type(s) | JOURNAL ARTICLE
| | PubMed ID | 19884342 |
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