Synthesis and Characterization of Informational Molecules Formed under Prebiotic Conditions

All processes in extant biology are possible and facilitated by information encoded in polymers. Therefore, the origin of informational molecules had to be a crucial step in the origin of life on Earth. An important molecule in this context is RNA and the RNA World has been hypothesized as a crucial step in the transition from chemistry to biology. However, the RNA molecule is comprised of intra-molecular bonds, which are prone to hydrolysis, especially under the harsh conditions that are thought to have been prevalent on the early Earth [1]. Furthermore, the formation of nucleotides with extant bases, and their subsequent polymerization, have both been problematic, to say the least. Certain environmental niches, such as volcanic geothermal pools, allow the formation of RNA-like polymers, under dehydrating-rehydrating (DH-RH) conditions, by potentially forming kinetic traps [2]. However, the low pH and high temperature conditions that are required for such polymerization to occur also result in the cleavage of the N-glycosidic bond, thereby producing polymers with abasic sites [3]. In the first part of the present study, we set out to characterize the effect of prolonged cycling, under DH-RH conditions, on the stability of resultant molecules and also looked at how they might affect the product distribution. Our observations indicate lower fitness for modern nucleobases under prebiotically relevant conditions. These results are also supported by older experiments wherein formation of nucleosides with extant bases was shown to be difficult.