Can molecules exhibit biological behaviour?

An RNA that synthesises RNA
Artwork: @RuneKidmose

We have developed catalytic RNA molecules – ribozymes – that can copy RNA sequences^1,2. These RNA polymerase ribozymes transmit genetic information through the generations, like protein polymerases do in biology. However, in other respects – such as their use of 3-letter building blocks – these ribozymes behave more like biology’s ribosomes, suggesting that primordial biology worked differently. We are using physicochemical cycles to get these molecules to exponentially replicate parts of themselves³, and find a route to self-replicating molecules as a model of nascent biology.

Can ribozymes catalyse prebiotic chemistry?

Protocell concept

The chemical pathways harnessed by early biology may have been different to those that succeeded them in modern biology. We collaborate with the Powner group at UCL Chemistry to understand the impact of potentially prebiotic chemistries⁴ upon the molecular ecology of RNA. We are particularly interested in whether such chemistries can confer additional capabilities upon ribozymes, and which catalytic opportunities ribozymes might evolve to exploit. We hope to build a better picture of the early development of RNA-based life in its chemical and geological context.

Can we narrow the gap between chemistry and life?

Ice eutectic phase microstructure

There is a forbidding gulf between the transience of chemistry, and the complexity needed to kick-start RNA-based life. But opportunities exist to narrow this gap: geochemical environments⁵, peptides⁶, systems chemistry, and sequence pool behaviours^1,3 could help heritable function arise more easily from chemical systems, and contribute to plausible models for the emergence of early biology. Testing the limits of RNA catalysis and evolution could suggest new ways to apply the power of evolution in simple systems and in a broader polymer chemical space.