Greenwell H Chris, Coveney Peter V
Centre for Computational Science, Christopher Ingold Laboratory, University College London, 20 Gordon Street, London, WC1H 0AJ, UK.
Orig Life Evol Biosph. 2006 Feb;36(1):13-37. doi: 10.1007/s11084-005-2068-2.
One of the fundamental difficulties when considering the origin of life on Earth is the identification of an emergent system that not only replicated, but also had the capacity to undergo discrete mutation in such a way that following generations might inherit and pass on the mutation. We speculate that the layered double hydroxide (LDH) minerals are plausible candidates for a proto-RNA molecule. We describe a hypothetical LDH-like system which, when intercalated with certain anions, forms crystals with a high degree of internal order giving rise to novel information storage structures in which replication fidelity is maintained, a concept we use to propose an explanation for interstratification in terephthalate LDHs. The external surfaces of these hypothetical crystals provide active sites whose structure and chemistry is dictated by the internal information content of the LDH. Depending on the LDH polytype, the opposing external surfaces of a crystal may give rise to reactive sites that are either complementary or mirror images of each other, and so may be chiral. We also examine similarities between these proposed "proto-RNA" structures and the DNA that encodes the hereditary information in life today, concluding with a hypothetical scenario wherein these proto-RNA molecules predated the putative RNA-world.
在思考地球生命起源时，一个基本难题是确定一个不仅能自我复制，还能以某种方式发生离散突变，使后代能够继承并传递该突变的新兴系统。我们推测层状双氢氧化物（LDH）矿物可能是原始RNA分子的候选者。我们描述了一个类似LDH的假设系统，当它与某些阴离子插层时，会形成具有高度内部秩序的晶体，从而产生新的信息存储结构，其中复制保真度得以维持，我们用这个概念来解释对苯二甲酸根LDH中的层间交替现象。这些假设晶体的外表面提供了活性位点，其结构和化学性质由LDH的内部信息内容决定。根据LDH的多型性，晶体相对的外表面可能产生相互互补或互为镜像的反应位点，因此可能具有手性。我们还研究了这些提出的“原始RNA”结构与当今编码生命遗传信息的DNA之间的相似性，最后提出一个假设情景，即在假定的RNA世界之前存在这些原始RNA分子。
