Eukaryotic wobble uridine modifications promote a functionally redundant decoding system
Eukaryotic wobble uridine modifications promote a functionally redundant decoding system
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DOI：
10.1128/mcb.01542-07
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发表时间：
2008-05-01
影响因子：
5.3
通讯作者：
Bystrom, Anders S.
中科院分区：
文献类型：
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作者：
Johansson, Marcus J. O.;Esberg, Anders;Bystrom, Anders S.
trna的翻译解码特性是由自然发生的核苷修饰调节的。真核胞质trna中位于摆动位置的嘌呤（核苷34 [U-34]）通常含有5-甲氧基羰基甲基（mcm(5)）或5-氨基甲基甲基（ncm(5)）侧链，有时还含有2-硫（s(2)）或2'- o -甲基。虽然已经提出了各种模型来解释这些修饰的作用，但它们在体内的功能尚未明确。在这项研究中，我们利用最近表征的缺乏修饰的酿酒酵母细胞来测试体内的摆动规律。我们发现mcm(5)和ncm(5)侧链促进了g端密码子的解码，并发mcm(5)和s(2)组促进了A端和g端密码子的读取。此外，对mcm(5)U(34)-和一些ncm(5)U(34)-含trna有效读取g端密码子的观察挑战了真核生物不使用U- g摆动的概念。
The translational decoding properties of tRNAs are modulated by naturally occurring modifications of their nucleosides. Uridines located at the wobble position (nucleoside 34 [U-34]) 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 (s(2)) 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 mcm(5) and ncm(5) side chains promote decoding of G-ending codons and that concurrent mcm(5) and s(2) groups improve reading of both A- and G-ending codons. Moreover, the observation that the mcm(5)U(34)- and some ncm(5)U(34)-containing tRNAs efficiently read G-ending codons challenges the notion that eukaryotes do not use U-G wobbling.