Errors and alternatives in prebiotic replication and catalysis.

Area of Science:

• Origin of life studies
• Prebiotic chemistry
• Molecular evolution

Background:

• Leslie Orgel's work on nonenzymatic nucleic acid replication and artificial selection of RNA aptamers and ribozymes.
• Pessimism surrounding 'naked gene' theories for the origin of life.
• Acknowledged need for complex and dynamic environments for primitive RNA replication and catalysis.

Purpose of the Study:

• To propose alternative theories for the origin of life that bridge 'naked gene' and metabolic theories.
• To address challenges in RNA replication and catalysis, such as efficiency gains and information content.
• To explore the role of short oligomers and heterogeneous complexes in prebiotic systems.

Main Methods:

• Re-evaluation of 'naked gene' theories in light of current research.
• Proposal of alternative models for early genetic systems.
• Consideration of heterogeneous complexes of short oligomers for catalytic functions.
• Incorporation of replication errors with chemically reactive nucleotides.

Main Results:

• Low probability of finding RNA aptamers/ribozymes is less concerning than poor efficiency gains with increased information.
• Complex, dynamic environments are crucial for early RNA replication and catalysis.
• Short oligomers in heterogeneous complexes may offer solutions to stability, binding, reactivity, and specificity challenges.
• Replication errors introducing reactive nucleotides could enable dual function (inert/catalytic) for RNA sequences.

Conclusions:

• Primitive replication and catalysis likely occurred in complex environments, not solely with 'naked genes'.
• Alternative models involving short oligomers and heterogeneous complexes offer viable pathways for prebiotic chemistry.
• Replication errors can be a source of functional innovation, enabling RNA to act as both information carriers and catalysts.