Palacios-Pérez Miryam, José Marco V
Theoretical Biology Group, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México CDMX, C.P. 04510, Mexico.
Biosystems. 2019 Jul;181:1-10. doi: 10.1016/j.biosystems.2019.04.007. Epub 2019 Apr 14.
The attempt to delineate the essential features that characterized life in its beginnings and the understanding of how those features evolved, represent important scientific challenges. While there have been varied efforts in the elucidation of how the first biomolecules arose from a prebiotic environment, there remains important gaps towards the characterization of the complete repertoire of the Last Universal Common Ancestor (LUCA). We portray a step-wise proteome evolution, by looking at the phenotype encoded by each one of the genetic codes that were appearing along evolution, beginning with the primeval genetic code and then with two intermediate Extended RNA codes, which finally shaped the current Standard Genetic Code (SGC). Notably, all molecules involved in translation, such as ribosomal proteins and all tRNA synthetases, were already present before LUCA. The metabolism belonged to extremophiles as hinted by the presence of reverse gyrase and acetyl coenzyme A synthase. Furthermore, we predict the structure and possible ligands of the proteins retrieved. We have forged a bridge between the hitherto unknown proteome of progenotes and the proteome of LUCA.
描绘生命起源时的基本特征以及理解这些特征如何演化，是重要的科学挑战。虽然在阐明首批生物分子如何从益生元环境中产生方面已经做出了各种努力，但在表征最后共同祖先（LUCA）的完整基因库方面仍存在重大差距。我们通过观察进化过程中出现的每个遗传密码所编码的表型，描绘了一个逐步的蛋白质组进化过程，从原始遗传密码开始，然后是两个中间的扩展RNA密码，最终形成了当前的标准遗传密码（SGC）。值得注意的是，所有参与翻译的分子，如核糖体蛋白和所有tRNA合成酶，在LUCA出现之前就已经存在。正如反向回旋酶和乙酰辅酶A合成酶的存在所暗示的那样，新陈代谢属于极端微生物。此外，我们预测了所检索蛋白质的结构和可能的配体。我们在迄今未知的原始生物蛋白质组和LUCA的蛋白质组之间架起了一座桥梁。
