Our knowledge regarding the early steps in the formation of evolvable life and what constitutes the minimal molecular basis of life remains far from complete. The recent emergence of systems chemistry reinvigorated the investigation of systems of self-replicating molecules to address these questions. Most of these studies focus on single replicators and the effects of replicators on the emergence of other replicators remains under-investigated. Here we show the cross-catalyzed emergence of a novel self-replicator from a dynamic combinatorial library made from a threonine containing peptide building block, which, by itself, only forms trimers and tetramers that do not replicate. Upon seeding of this library with different replicators of different macrocycle size (hexamers and octamers), we observed the emergence of hexamer replicator consisting of six units of the threonine peptide only when it is seeded with an octamer replicator containing eight units of a serine building block. These results reveal for the first time how a new replicator can emerge in a process that relies critically on the assistance by another replicator through cross-catalysis and that replicator composition is history dependent.

中文翻译：

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从动态组合库中出现新的自我复制器需要特定的预先存在的复制器

我们对形成可进化生命的早期步骤以及构成生命的最小分子基础的知识仍然远远不够。系统化学的最新出现使人们对解决这些问题的自我复制分子系统的研究重新焕发了活力。这些研究大多数集中在单一复制者上，复制者对其他复制者出现的影响仍未得到充分研究。在这里，我们显示了由含有苏氨酸的肽结构单元制成的动态组合文库中交叉催化出现的新型自我复制子，该结构本身仅形成了不复制的三聚体和四聚体。在此库中植入了具有不同大环大小的不同复制子（六聚体和八聚体）后，我们观察到只有当六聚体复制子与包含八个单元丝氨酸结构单元的八聚体复制子一起播种时，才会出现由六单元苏氨酸肽组成的六聚体复制子。这些结果首次揭示了新的复制子如何在一个过程中出现，该过程关键地依赖于另一个复制子通过交叉催化的协助，并且复制子的组成与历史有关。