Acid-catalyzed RNA-oligomerization from 3´,5´-cGMP.

The assembly of ancient informational polymers from nucleotide precursors is the central challenge of life's origin on our planet. Among the possible solutions, dry polymerization of 3´,5´-cyclic guanosine monophosphate (3´,5´-cGMP) has been proposed as a candidate to create oligonucleotides of the length of 15-20 nucleotides. However, the reported sensitivity of the reaction to the presence of cations raised questions if this chemistry could be relevant in a geological context. The experiments in the current study show that the presence of cations is not restrictive as long as the reaction is conducted in an acidic environment, in contrast to previous reports that suggested optimal conditions at pH 9.