Common origins of RNA, protein and lipid precursors in a cyanosulfidic protometabolism
作者:Bhavesh H. Patel、Claudia Percivalle、Dougal J. Ritson、Colm D. Duffy、John D. Sutherland
DOI:10.1038/nchem.2202
日期:2015.4
A minimal cell can be thought of as comprising informational, compartment-forming and metabolic subsystems. To imagine the abiotic assembly of such an overall system, however, places great demands on hypothetical prebiotic chemistry. The perceived differences and incompatibilities between these subsystems have led to the widely held assumption that one or other subsystem must have preceded the others. Here we experimentally investigate the validity of this assumption by examining the assembly of various biomolecular building blocks from prebiotically plausible intermediates and one-carbon feedstock molecules. We show that precursors of ribonucleotides, amino acids and lipids can all be derived by the reductive homologation of hydrogen cyanide and some of its derivatives, and thus that all the cellular subsystems could have arisen simultaneously through common chemistry. The key reaction steps are driven by ultraviolet light, use hydrogen sulfide as the reductant and can be accelerated by Cu(I)âCu(II) photoredox cycling. A minimal cell â one that has all the minimum requirements for life â is still a complex entity comprising informational, compartment-forming and metabolic subsystems. Here it is shown that, contrary to previous assumptions, a common prebiotically plausible chemistry can give rise to building blocks for all the subsystems.
一个最小细胞可以被认为由信息传递、分隔形成和代谢子系统组成。然而,要想象这样一个整体系统的非生物组装,对假设的产前化学提出了很高的要求。这些子系统之间感知到的差异和不兼容性导致了广泛持有的假设,即其中一个或另一个子系统必须先于其他子系统出现。在这里,我们通过检查从产前可能的中间产物和一碳供体分子组装各种生物分子构建块,来实验调查这个假设的有效性。我们表明,核糖核苷酸、氨基酸和脂质的先驱都可以通过氢氰酸及其一些衍生物的还原同系化来衍生,因此所有细胞子系统可能都通过共同的化学同时出现。关键反应步骤由紫外线驱动,使用硫化氢作为还原剂,并且可以通过Cu(I)-Cu(II)光氧化还原循环加速。一个最小细胞——一个具有生命所有最低要求的细胞——仍然是一个复杂的实体,包含信息传递、分隔形成和代谢子系统。这里表明,与之前的假设相反,一个普遍的产前可能化学可以产生所有子系统的构建块。