RNA species play host to a plethora of post-transcriptional modifications which together make up the epitranscriptome. 5-methyluridine (m5U) is one of the most common modifications made to cellular RNA, where it is found almost ubiquitously in bacterial and eukaryotic cytosolic tRNAs at position 54. Here, we demonstrate that m5U54 in human mitochondrial tRNAs is catalysed by the nuclear-encoded enzyme TRMT2B, and that its repertoire of substrates is expanded to ribosomal RNAs, catalysing m5U429 in 12S rRNA. We show that TRMT2B is not essential for viability in human cells and that knocking-out the gene shows no obvious phenotype with regards to RNA stability, mitochondrial translation, or cellular growth.

中文翻译：

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TRMT2B负责人线粒体中的tRNA和rRNA m5U甲基化。

RNA种类充当大量转录后修饰的宿主，这些修饰一起构成了转录组。5-甲基尿苷（m5U）是对细胞RNA进行的最常见修饰之一，在细菌和真核细胞质tRNA的第54位几乎无处不在。在这里，我们证明了人类线粒体tRNA中的m5U54被核仁催化编码TRMT2B酶，并且其底物库扩展到核糖体RNA，在12S rRNA中催化m5U429。我们显示TRMT2B并不是人类细胞中生存能力所必需的，并且敲除该基因在RNA稳定性，线粒体翻译或细胞生长方面没有表现出明显的表型。