Lower temperature optimum of a smaller, fragmented triphosphorylation ribozyme

Area of Science:

• Origin of Life Studies
• RNA Biochemistry
• Prebiotic Chemistry

Background:

• The RNA world hypothesis proposes early life used catalytic RNAs (ribozymes) for replication.
• Existing ribozymes are often too long for prebiotic plausibility or synthesis by polymerase ribozymes.
• A previously developed 96-nucleotide ribozyme activated trimetaphosphate to generate 5'-triphosphate, mimicking an energy source.

Purpose of the Study:

• To reduce the length of a functional ribozyme to increase prebiotic plausibility.
• To investigate if fragmented ribozymes retain catalytic activity and alter properties.
• To explore the implications of shorter ribozymes for early life conditions.

Main Methods:

• Fragmented a 96-nucleotide ribozyme into smaller RNA strands.
• Successively removed the longest double-stranded region of the ribozyme.
• Assessed the catalytic activity and temperature optimum of the resulting fragmented ribozyme.

Main Results:

• Created a functional ribozyme composed of fragments no longer than 34 nucleotides.
• The fragmented ribozyme maintained the ability to generate chemically activated 5'-phosphate.
• The temperature optimum shifted from ~40 °C (parent ribozyme) to ~20 °C (fragmented ribozyme).

Conclusions:

• Shorter, fragmented ribozymes are feasible and retain essential catalytic functions.
• The reduced temperature optimum suggests fragmented ribozymes may have functioned in cooler early Earth environments.
• This work provides a more plausible model for energy generation in the early RNA world.