Dual pathways of tRNA hydroxylation ensure efficient translation by expanding decoding capability
Dual pathways of tRNA hydroxylation ensure efficient translation by expanding decoding capability
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DOI：
10.1038/s41467-019-10750-8
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发表时间：
2019-06
影响因子：
16.6
通讯作者：
Y. Sakai;S. Kimura;Tsutomu Suzuki
中科院分区：
文献类型：
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作者：
Y. Sakai;S. Kimura;Tsutomu Suzuki
在细菌tRNA中，反密码子第一位的5-羧甲氧基尿苷(Cmo5U)及其衍生物促进了非Watson-Crick碱基与密码子第三位的鸟苷和嘧啶配对，从而扩大了解码能力。然而，它们的生物发生和生理作用仍有待研究。利用反向遗传学和比较基因组学，我们确定了导致5-羟基尿苷(Ho5U)形成的两个因素，这是cmo5U合成的第一步：TrhP(以前称为YegQ)是一个多肽酶U32家族蛋白，参与预苯醚依赖的ho5U的形成；TrhO(以前称为YceA)是一个罗丹家族蛋白，在有氧条件下催化氧依赖的ho5U的形成并绕过tRNAs中的cmo5U的生物发生。缺乏这两种基因的E.colistrains表现出对温度敏感的表型，并且解码以G(GCG和UCG)结尾的密码子的效率低于野生型菌株。这些发现证实了tRNA羟化确保了蛋白质合成过程中的有效解码。
In bacterial tRNAs, 5-carboxymethoxyuridine (cmo5U) and its derivatives at the first position of the anticodon facilitate non-Watson–Crick base pairing with guanosine and pyrimidines at the third positions of codons, thereby expanding decoding capabilities. However, their biogenesis and physiological roles remained to be investigated. Using reverse genetics and comparative genomics, we identify two factors responsible for 5-hydroxyuridine (ho5U) formation, which is the first step of the cmo5U synthesis: TrhP (formerly known as YegQ), a peptidase U32 family protein, is involved in prephenate-dependent ho5U formation; and TrhO (formerly known as YceA), a rhodanese family protein, catalyzes oxygen-dependent ho5U formation and bypasses cmo5U biogenesis in a subset of tRNAs under aerobic conditions.E. colistrains lacking bothtrhPandtrhOexhibit a temperature-sensitive phenotype, and decode codons ending in G (GCG and UCG) less efficiently than the wild-type strain. These findings confirm that tRNA hydroxylation ensures efficient decoding during protein synthesis.