Zhang Hong-Yu
Shandong Provincial Research Center for Bioinformatic Engineering and Technique, Center for Advanced Study, Shandong University of Technology, Zibo 255049, PR China.
Biochem Biophys Res Commun. 2007 Aug 3;359(3):403-5. doi: 10.1016/j.bbrc.2007.05.115. Epub 2007 May 25.
One of the most intriguing aspects of life is that despite the diversified apparent shapes, similar building blocks and infrastructures, such as standard amino acids and canonical genetic codes, are shared by most life on Earth. Thus, it is challenging to explore: why nature just selects these building blocks and strategies from numerous candidates to construct life? Was this deterministic or fortuitous? Thanks to the rapid progress in genomics, bioinformatics and synthetic biology, more and more basic principles underlying life design and construction were disclosed in the past decade. However, since the origin of early life is substantially a chemical process, to understand the enigma of life origin, chemists' efforts can not be neglected. In this paper, we focus on the evolution of standard amino-acid alphabet and indicate that chemistry, especially thermodynamics, is indeed critical to understanding the forming mechanisms of amino-acid alphabet. It is revealed that nature prefers low free energy and thus ubiquitous (cheap) small amino acids when beginning to build life, which is compatible with many recent findings from genomics and bioinformatics.
生命最引人入胜的一个方面在于，尽管生命形式表面上多种多样，但地球上的大多数生命都共享着相似的构建模块和基础设施，比如标准氨基酸和规范的遗传密码。因此，探索以下问题颇具挑战性：为何大自然仅从众多候选物中挑选出这些构建模块和策略来构建生命？这是由某种确定性因素导致的，还是偶然发生的？得益于基因组学、生物信息学和合成生物学的飞速发展，在过去十年里，越来越多生命设计与构建背后的基本原理被揭示出来。然而，由于早期生命的起源本质上是一个化学过程，要理解生命起源之谜，化学家的努力不可忽视。在本文中，我们聚焦于标准氨基酸字母表的进化，并指出化学，尤其是热力学，对于理解氨基酸字母表的形成机制确实至关重要。研究表明，大自然在开始构建生命时倾向于低自由能，因而选择了普遍存在（廉价）的小氨基酸，这与基因组学和生物信息学最近的许多发现相吻合。
