To enable repeated cycles of RNA replication, the two strands of the
product must be separated and then copied before they reanneal. In
solution, complementary RNA strands anneal orders of magnitude more
rapidly than non-enzymatic template copying, rendering multiple
rounds of RNA replication a formidable challenge. Our recent
studies enabled further rounds of copying by using oligoarginine
peptides. These peptides slow the annealing of complementary RNAs
by up to several thousand-fold while still allowing short primers
and activated monomers to bind to template strands. As a result
template-directed primer extension can proceed even in the presence
of the complementary strand to the template. Remarkably, the
template copying occurs within a phase-separated condensed state, or
coacervate. Future work will focus on elucidating the molecular
mechanism of this unusual RNA-peptide interaction.
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