Nonenzymatic RNA-templated Synthesis of N3′→P5′ Phosphoramidate DNA

Abstract

The RNA world hypothesis describes a scenario where early life forms relied on RNA to govern both inheritance and catalyze useful chemical reactions. Prior to the emergence of enzymes capable of replicating the RNA genome, a nonenzymatic replication process would have been necessary to initiate Darwinian Evolution. However, the one-pot nonenzymatic RNA chemical copying of templates with mixed-sequences is insufficient to generate strand products long enough to encode useful function. The use of alternate (RNA-like) genetic polymers may overcome hurdles associated with RNA copying, and further our understanding of nonenzymatic copying chemistry. This protocol describes the nonenzymatic copying of RNA templates into N3′→P5′ phosphoramidate DNA (3′-NP-DNA). We describe, in detail, the synthesis of 3′-amino-2′,3′-dideoxyribonucleotide monomers activated with 2-aminoimidazole (3′-NH2-2AIpddN), and their use in template-directed polymerization.