Eukaryotic wobble uridine modifications promote a functionally redundant decoding system.
2008 (English)In: Molecular and Cellular Biology, ISSN 0270-7306, E-ISSN 1098-5549, Vol. 28, no 10, 3301-3312 p.Article in journal (Refereed) Published
The translational decoding properties of tRNAs are modulated by naturally occurring modifications of their nucleosides. Uridines located at the wobble position (nucleoside 34 [U34]) in eukaryotic cytoplasmic tRNAs often harbor a 5-methoxycarbonylmethyl (mcm(5)) or a 5-carbamoylmethyl (ncm(5)) side chain and sometimes an additional 2-thio (s2) or 2'-O-methyl group. Although a variety of models explaining the role of these modifications have been put forth, their in vivo functions have not been defined. In this study, we utilized recently characterized modification-deficient Saccharomyces cerevisiae cells to test the wobble rules in vivo. We show that mcm5 and ncm5 side chains promote decoding of G-ending codons and that concurrent mcm5 and s2 groups improve reading of both A- and G-ending codons. Moreover, the observation that the mcm5U34- and some ncm5U34-containing tRNAs efficiently read G-ending codons challenges the notion that eukaryotes do not use U-G wobbling.
Place, publisher, year, edition, pages
2008. Vol. 28, no 10, 3301-3312 p.
IdentifiersURN: urn:nbn:se:umu:diva-20533DOI: 10.1128/MCB.01542-07PubMedID: 18332122OAI: oai:DiVA.org:umu-20533DiVA: diva2:208856