Transfer RNAs (tRNAs) are essential adaptors that mediate translation of the genetic code. These molecules undergo a variety of post-transcriptional modifications, which expand their chemical reactivity while influencing their structure, stability, and functionality. Chemical modifications to tRNA ensure translational competency and promote cellular viability. Hence, the placement and prevalence of tRNA modifications affects the efficiency of aminoacyl tRNA synthetase (aaRS) reactions, interactions with the ribosome, and transient pairing with messenger RNA (mRNA). The synthesis and abundance of tRNA modifications respond directly and indirectly to a range of environmental and nutritional factors involved in the maintenance of metabolic homeostasis. The dynamic landscape of the tRNA epitranscriptome suggests a role for tRNA modifications as markers of cellular status and regulators of translational capacity. This review discusses the non-canonical roles that tRNA modifications play in central metabolic processes and how their levels are modulated in response to a range of cellular demands.

中文翻译：

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tRNA 修饰在微生物中的课外功能

转移 RNA (tRNA) 是介导遗传密码翻译的重要适配器。这些分子经历了多种转录后修饰，在影响其结构、稳定性和功能的同时扩大了它们的化学反应性。tRNA 的化学修饰可确保翻译能力并促进细胞活力。因此，tRNA 修饰的位置和普遍性会影响氨酰 tRNA 合成酶 (aaRS) 反应的效率、与核糖体的相互作用以及与信使 RNA (mRNA) 的瞬时配对。tRNA 修饰的合成和丰度直接或间接对一系列参与维持代谢稳态的环境和营养因素作出反应。tRNA 表观转录组的动态景观表明 tRNA 修饰作为细胞状态标志物和翻译能力调节剂的作用。本综述讨论了 tRNA 修饰在中枢代谢过程中发挥的非规范作用，以及它们的水平如何根据一系列细胞需求进行调节。