The RNA i-Motif in the Primordial RNA World

Area of Science:

• Astrobiology
• Biochemistry
• Molecular Biology

Background:

• The RNA world hypothesis posits RNA preceded DNA and proteins as the primary life molecule.
• Cytosine instability (deamination) is a significant challenge to the RNA world hypothesis.
• RNA can form complex structures like quadruplexes, influencing its function and stability.

Purpose of the Study:

• To propose a mechanism for cytosine stabilization in the primordial RNA world.
• To explore the potential functional roles of cytosine-rich RNA structures.

Main Methods:

• Theoretical proposal of the RNA i-motif structure.
• Analysis of cytosine deamination rates within the i-motif structure.
• Consideration of ligand binding to RNA i-motifs.

Main Results:

• The RNA i-motif structure, formed by cytosine residues under acidic conditions, can protect cytosine from deamination.
• This stabilization increases the lifetime of cytosine, addressing a key RNA world challenge.
• RNA i-motifs may facilitate ligand binding, enabling early RNA functions.

Conclusions:

• The RNA i-motif offers a plausible solution for cytosine stability in the early RNA world.
• Further research on cytosine deamination rates and ligand interactions in i-motifs is crucial.
• Investigating RNA i-motifs could provide critical insights into the origin of life.