Transfer RNAs (tRNAs) are the most highly modified cellular RNAs, both with respect to the proportion of nucleotides that are modified within the tRNA sequence and with respect to the extraordinary diversity in tRNA modification chemistry. However, the functions of many different tRNA modifications are only beginning to emerge. tRNAs have two general clusters of modifications. The first cluster is within the anticodon stem-loop including several modifications essential for protein translation. The second cluster of modifications is within the tRNA elbow, and roles for these modifications are less clear. In general, tRNA elbow modifications are typically not essential for cell growth, but nonetheless several tRNA elbow modifications have been highly conserved throughout all domains of life. In addition to forming modifications, many tRNA modifying enzymes have been demonstrated or hypothesized to also play an important role in folding tRNA acting as tRNA chaperones. In this review, we summarize the known functions of tRNA modifying enzymes throughout the lifecycle of a tRNA molecule, from transcription to degradation. Thereby, we describe how tRNA modification and folding by tRNA modifying enzymes enhance tRNA maturation, tRNA aminoacylation, and tRNA function during protein synthesis, ultimately impacting cellular phenotypes and disease.

中文翻译：

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RNA 修饰酶塑造 tRNA 生物发生和功能


转移 RNA (tRNA) 是修饰程度最高的细胞 RNA，无论是在 tRNA 序列内修饰的核苷酸比例方面，还是在 tRNA 修饰化学的非凡多样性方面。然而，许多不同 tRNA 修饰的功能才刚刚开始显现。 tRNA 有两大类修饰。第一个簇位于反密码子茎环内，包括蛋白质翻译所必需的几个修饰。第二组修饰位于 tRNA 肘部内，这些修饰的作用尚不清楚。一般来说，tRNA 肘部修饰通常对细胞生长不是必需的，但尽管如此，一些 tRNA 肘部修饰在生命的所有领域中都高度保守。除了形成修饰之外，许多 tRNA 修饰酶已被证明或假设在充当 tRNA 伴侣的 tRNA 折叠中也发挥重要作用。在这篇综述中，我们总结了 tRNA 修饰酶在 tRNA 分子从转录到降解的整个生命周期中的已知功能。因此，我们描述了 tRNA 修饰酶的 tRNA 修饰和折叠如何增强 tRNA 成熟、tRNA 氨酰化和蛋白质合成过程中 tRNA 的功能，最终影响细胞表型和疾病。