Derivation and Progress of Non-enzymatic RNA Replication

Abstract

Molecular replication has branched into two parts, on one hand, it involves the non-informational copying of polymers which provides a replication environment indirectly, and on the other hand, the informational copying, including DNA or RNA replication, is a direct replication system. On account of the central dogma of molecular biology, after the transcription from DNA to mRNA, some living organisms require a specific RNA polymerase to catalyse and control the reaction of RNA self-replication. Based on the RNA world hypothesis, the self-replication of RNA at the earlier stage of the origin of life occurred under an enzyme-free condition. RNA replication process needs three steps: (a) separation of the duplex, (b) monomer extension of each strand, and (c) the end to end propagation of RNA strand. It was suggested that non-enzymatic RNA copying could take place in the presence of metal ions, like Mg or Fe. Strand separation can be achieved by pH or temperature oscillation, and the RNA monomer extension could be attainable with the involvement of two activated nucleotides. This review gives a brief summary of the accomplishments scientists have made, and also concerns about several impediments in this process as well as their solutions.