G&L Kyosei Institute, The Keihanna Academy of Science and Culture (KASC), Keihanna Interaction Plaza, Lab. Wing 3F, 1-7 Hikaridai, Seika-cho, Souraku, Kyoto 619-0237, Japan.
International Institute for Advanced Studies, Kizugawadai 9-3, Kizugawa, Kyoto 619-0225, Japan.
Genes (Basel). 2023 Jan 31;14(2):375. doi: 10.3390/genes14020375.
Correspondence relations between codons and amino acids are determined by genetic code. Therefore, genetic code holds a key of the life system composed of genes and protein. According to the GNC-SNS primitive genetic code hypothesis, which I have proposed, it is assumed that the genetic code originated from GNC code. In this article, first, it is discussed from a standpoint of primeval protein synthesis, why four [GADV]-amino acids were selected and used in the first GNC code. Next, it is explained from another standpoint of the most primitive anticodon-stem loop tRNAs (AntiC-SL tRNAs), how four GNCs were selected for the first codons. Furthermore, in the last section of this article, I will explain my idea of how the correspondence relations between four [GADV]-amino acids and four GNC codons were established. Namely, the origin and evolution of the genetic code was discussed comprehensively from several aspects of [GADV]-proteins, [GADV]-amino acids, GNC codons, and anticodon stem-loop tRNAs (AntiC-SL tRNAs), which relate each other to the origin of the genetic code, as integrating GNC code frozen-accident theory, coevolution theory, and adaptive theory on the origin of the genetic code.
密码子与氨基酸之间的对应关系由遗传密码决定。因此，遗传密码是由基因和蛋白质组成的生命系统的关键。根据我提出的 GNC-SNS 原始遗传密码假说，遗传密码起源于 GNC 码。在本文中，首先从原始蛋白质合成的角度讨论了为什么在第一个 GNC 码中选择并使用了四个[GADV]-氨基酸。接下来，从最原始的反密码子茎环 tRNA（AntiC-SL tRNA）的另一个角度解释了为什么选择了四个 GNC 作为第一个密码子。此外，在本文的最后一节中，我将解释我关于如何建立四个[GADV]-氨基酸和四个 GNC 密码子之间对应关系的想法。也就是说，从[GADV]-蛋白、[GADV]-氨基酸、GNC 密码子和反密码子茎环 tRNA（AntiC-SL tRNA）等几个方面，全面探讨了遗传密码的起源和进化，这些方面相互关联，涉及到遗传密码的起源，整合了 GNC 码冻结事件理论、共同进化理论和遗传密码起源的适应理论。
