小柯机器人

英国剑桥生物医学园区John D. Sutherland研究组近日取得一项新成果。他们揭示了RNA嘧啶和DNA嘌呤核苷在生命起源之前就已形成。该项研究成果在线发表在2020年6月3日的《自然》上。

研究人员完成了高效、立体、区域和呋喃糖基选择性嘌呤脱氧核糖核苷——脱氧腺苷和脱氧肌苷的非生物合成。研究人员的合成方法使用了经典嘧啶核糖核苷（胞苷和尿苷）非生物合成中的关键中间体，并且发现一经合成，嘧啶在嘌呤脱氧核糖核苷的整个合成过程中一直存在，从而形成脱氧腺苷、脱氧肌苷、胞苷和尿苷。这些结果支持了嘌呤脱氧核糖核苷和嘧啶核糖核苷可能在生命出现之前并存的观点。

研究人员表示，对第一个遗传聚合物是什么的争论一直存在。尽管“ RNA世界”理论认为RNA是微生物存在之前的第一个可复制遗传信息载体，早于生命开始之前。但其他证据表明，生命也可能始于异质核酸遗传系统，其中包括RNA和DNA。这样的理论简化了最终从RNA中“同质DNA”作为主要遗传信息存储分子的“遗传接管”机制，但是在相同的原始地球化学情况下，需要RNA和DNA结构单元的选择性非生物合成。

附：英文原文

Title: Selective prebiotic formation of RNA pyrimidine and DNA purine nucleosides

Author: Jianfeng Xu, Vclav Chmela, Nicholas J. Green, David A. Russell, Mikoaj J. Janicki, Robert W. Gra, Rafa Szabla, Andrew D. Bond, John D. Sutherland

Issue&Volume: 2020-06-03

Abstract: The nature of the first genetic polymer is the subject of major debate1. Although the ‘RNA world’ theory suggests that RNA was the first replicable information carrier of the prebiotic era—that is, prior to the dawn of life2,3—other evidence implies that life may have started with a heterogeneous nucleic acid genetic system that included both RNA and DNA4. Such a theory streamlines the eventual ‘genetic takeover’ of homogeneous DNA from RNA as the principal information-storage molecule, but requires a selective abiotic synthesis of both RNA and DNA building blocks in the same local primordial geochemical scenario. Here we demonstrate a high-yielding, completely stereo-, regio- and furanosyl-selective prebiotic synthesis of the purine deoxyribonucleosides: deoxyadenosine and deoxyinosine. Our synthesis uses key intermediates in the prebiotic synthesis of the canonical pyrimidine ribonucleosides (cytidine and uridine), and we show that, once generated, the pyrimidines persist throughout the synthesis of the purine deoxyribonucleosides, leading to a mixture of deoxyadenosine, deoxyinosine, cytidine and uridine. These results support the notion that purine deoxyribonucleosides and pyrimidine ribonucleosides may have coexisted before the emergence of life5.

DOI: 10.1038/s41586-020-2330-9

Source: https://www.nature.com/articles/s41586-020-2330-9

Nature：《自然》，创刊于1869年。隶属于施普林格·自然出版集团，最新IF：69.504
官方网址：http://www.nature.com/
投稿链接：http://www.nature.com/authors/submit_manuscript.html