Pust Marie-Madlen, Timmis Kenneth N, Tümmler Burkhard
Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany.
Institute of Microbiology, Technical University of Braunschweig, Braunschweig, Germany.
Environ Microbiol. 2022 Jul;24(7):2890-2894. doi: 10.1111/1462-2920.16033. Epub 2022 May 16.
The updated Wobble Hypothesis reasonably explains why some 40 tRNA species are sufficient to decode the 61 amino acid codons of the Universal Genetic Code. However, we still have no clue why eubacteria lack tRNA isoacceptors with ANN anticodons, whereas eukaryotes universally lack eight GNN anticodons, only one of which is also absent in bacteria. Direct tRNA sequencing could resolve the patterns of nucleoside modification that had been driving the divergent evolution in prokaryotes and eukaryotes, but this task will require the development of AI-supported base-callers that can recognize modified nucleosides without any subsequent analytical verification. Our knowledge of the bacterial tRNA landscape is moreover broadened by the recent discovery of antisense tRNAs and tRNA-derived fragments that should be examined in their roles for gene expression, translation, bacterial physiology or metabolism.
更新后的摆动假说合理地解释了为什么大约40种tRNA足以解码通用遗传密码的61种氨基酸密码子。然而，我们仍然不清楚为什么真细菌缺乏带有ANN反密码子的tRNA同工受体，而真核生物普遍缺乏8种GNN反密码子，其中只有一种在细菌中也不存在。直接对tRNA进行测序可以解析出驱动原核生物和真核生物趋异进化的核苷修饰模式，但这项任务需要开发人工智能支持的碱基识别器，这种识别器能够识别修饰核苷，而无需任何后续的分析验证。此外，最近发现的反义tRNA和tRNA衍生片段拓宽了我们对细菌tRNA格局的认识，应该对它们在基因表达、翻译、细菌生理学或代谢中的作用进行研究。
