Spontaneous formation and base pairing of plausible prebiotic nucleotides in water

Abstract

The RNA World hypothesis presupposes that abiotic reactions originally produced nucleotides, the monomers of RNA and universal constituents of metabolism. However, compatible prebiotic reactions for the synthesis of complementary (that is, base pairing) nucleotides and mechanisms for their mutual selection within a complex chemical environment have not been reported. Here we show that two plausible prebiotic heterocycles, melamine and barbituric acid, form glycosidic linkages with ribose and ribose-5-phosphate in water to produce nucleosides and nucleotides in good yields. Even without purification, these nucleotides base pair in aqueous solution to create linear supramolecular assemblies containing thousands of ordered nucleotides. Nucleotide anomerization and supramolecular assemblies favour the biologically relevant β-anomer form of these ribonucleotides, revealing abiotic mechanisms by which nucleotide structure and configuration could have been originally favoured. These findings indicate that nucleotide formation and selection may have been robust processes on the prebiotic Earth, if other nucleobases preceded those of extant life.

Three-Dimensional Uracil Network with Sodium as a Linker

“…[5][6][7][8][9][10] Although much progress has been made in creating 2D structures, few studies have succeeded in forming threedimensional (3D) spatially-controlled molecular arrangements on surfaces. Therefore, a number of approaches have been proposed for generating such 3D molecular arrangements.…”

Noncanonical RNA Nucleosides as Molecular Fossils of an Early Earth—Generation by Prebiotic Methylations and Carbamoylations

“…[19] This raises the question of whether life began with only the four canonical bases (A, C, G, and U) [20,21] or if an early pre-RNAw as chemically more diverse [22] and contained noncanonical nucleosides. [23][24][25] Finding evidence for this idea requires simple chemical synthetic routes compatible with geochemical models of early Earth that generate these noncanonical bases.H ere we show that the majority of methylated nucleosides,which play important roles in RNAs of all three domains of life,can be prebiotically generated by the reaction of canonical nucleosides with nitrosylated N-methylurea (1;S cheme 1). [23][24][25] Finding evidence for this idea requires simple chemical synthetic routes compatible with geochemical models of early Earth that generate these noncanonical bases.H ere we show that the majority of methylated nucleosides,which play important roles in RNAs of all three domains of life,can be prebiotically generated by the reaction of canonical nucleosides with nitrosylated N-methylurea (1;S cheme 1).…”

Nine Insights

“…Its molecules accommodate their irregular tetrahedral shape by rearranging themselves, emitting latent energy as ~4 µ infrared laser beams, ice-light [6]. During a long lasting primordial ice-age it crystallised in pools of liquid N 2 on Earth's poles.…”

“…During a long lasting primordial ice-age it crystallised in pools of liquid N 2 on Earth's poles. Icelight polarized by multiple reflection in cloud and surface ice selectively photo-phosphorylated nucleotides [6], turning Darwin's warm tropical waters to DNA noodle soup. The first bioactive molecules were tRNA analogues, transport DNAs.…”