Templated replication (or lack thereof) under prebiotically pertinent conditions.
Templated replication (or lack thereof) under prebiotically pertinent conditions.
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DOI：
10.1038/s41598-018-33157-9
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发表时间：
2018-10-09
影响因子：
4.6
通讯作者：
Rajamani S
中科院分区：
文献类型：
--
作者：
Bapat NV;Rajamani S
在生命的早期进化过程中，编码信息的准确复制对于功能性核酶的形成和繁殖至关重要。旨在了解与生物相关的非酶反应的研究主要使用活性核苷酸。然而，在生命前地球上是否存在集中的活性单体池是有争议的。在这项研究中，我们探索了使用更具生物相关性的5‘-核苷一磷酸(5’-NMP)进行非酶复制反应的可行性。这些反应涉及一种20聚体引发剂，是在火山地热条件下，在两亲分子存在的情况下进行的。有趣的是，延伸的引物与预期的全长21聚体产物不具有可比性。我们的结果表明延伸的底物中的氮碱基丢失。即使在降低温度和使用不同的再水化溶液后，这种现象仍然存在。我们预计，在将该单体添加到先前存在的低聚物中时，可能会丢失即将到来的5‘-NMP上的信息部分。值得注意的是，当使用5‘-核糖单磷酸时，观察到上述引物的多次添加导致杂化聚合物。这种杂化低聚物对于探索看似合理的交替核苷酸碱基的巨大化学空间可能是重要的，因此对原始信息聚合物的起源具有重要意义。
Accurate replication of encoded information would have been crucial for the formation and propagation of functional ribozymes during the early evolution of life. Studies aimed at understanding prebiotically pertinent nonenzymatic reactions have predominantly used activated nucleotides. However, the existence of concentrated pools of activated monomers on prebiotic Earth is debatable. In this study, we explored the feasibility of nonenzymatic copying reactions using the more prebiotically relevant 5′-nucleoside monophosphates (5′-NMP). These reactions, involving a 20-mer primer, were performed in the presence of amphiphiles, under volcanic geothermal conditions. Interestingly, the extended primer was not comparable to the expected full length 21-mer product. Our results suggest loss of the nitrogenous base in the extended primer. This phenomenon persisted even after lowering the temperature and when different rehydration solutions were used. We envisage that the loss of the informational moiety on the incoming 5′-NMP, might be occurring during addition of this monomer to the pre-existing oligomer. Significantly, when 5′-ribose monophosphate was used, multiple additions to the aforementioned primer were observed that resulted in hybrid polymers. Such hybrid oligomers could have been important for exploring a vast chemical space of plausible alternate nucleobases, thus having important implications for the origin of primitive informational polymers.