Department of Chemistry, The Pennsylvania State University, University Park, PA, 16802, USA.
Center for RNA Molecular Biology, The Pennsylvania State University, University Park, PA, 16802, USA.
Nat Commun. 2019 Jan 30;10(1):490. doi: 10.1038/s41467-019-08353-4.
Membraneless compartments, such as complex coacervates, have been hypothesized as plausible prebiotic micro-compartments due to their ability to sequester RNA; however, their compatibility with essential RNA World chemistries is unclear. We show that such compartments can enhance key prebiotically-relevant RNA chemistries. We demonstrate that template-directed RNA polymerization is sensitive to polycation identity, with polydiallyldimethylammonium chloride (PDAC) outperforming poly(allylamine), poly(lysine), and poly(arginine) in polycation/RNA coacervates. Differences in RNA diffusion rates between PDAC/RNA and oligoarginine/RNA coacervates imply distinct biophysical environments. Template-directed RNA polymerization is relatively insensitive to Mg concentration when performed in PDAC/RNA coacervates as compared to buffer, even enabling partial rescue of the reaction in the absence of magnesium. Finally, we show enhanced activities of multiple nucleic acid enzymes including two ribozymes and a deoxyribozyme, underscoring the generality of this approach, in which functional nucleic acids like aptamers and ribozymes, and in some cases key cosolutes localize within the coacervate microenvironments.
无膜隔室,如复杂凝聚物,由于其能够隔离 RNA,因此被假设为合理的前生物微隔室;然而,它们与基本的 RNA 世界化学物质的兼容性尚不清楚。我们表明,这样的隔室可以增强关键的前生物相关 RNA 化学。我们证明,模板指导的 RNA 聚合对聚阳离子的身份敏感,与聚(烯丙基胺)、聚(赖氨酸)和聚(精氨酸)相比,二烯丙基二甲基氯化铵(PDAC)在聚阳离子/RNA 凝聚物中表现更好。PDAC/RNA 和寡聚精氨酸/RNA 凝聚物之间的 RNA 扩散率差异暗示了不同的生物物理环境。与缓冲液相比,当在 PDAC/RNA 凝聚物中进行时,模板指导的 RNA 聚合对 Mg 浓度的相对不敏感,甚至可以在没有镁的情况下部分挽救反应。最后,我们展示了多种核酸酶的活性增强,包括两种核酶和一种脱氧核酶,这强调了这种方法的普遍性,其中功能性核酸如适体和核酶,以及在某些情况下关键共溶剂,都定位于凝聚物微环境中。