RNA double strand hybridization measured at the single molecule level

Area of Science:

• Molecular Biology
• Biophysics
• Genetics

Background:

• RNA hybridization is crucial for gene expression regulation.
• Single-stranded regulatory RNAs bind complementary messenger RNAs via Watson-Crick base pairing.

Purpose of the Study:

• To quantify the dissociation constants of complementary RNA single strands.
• To investigate RNA hybridization at the single-molecule level.
• To correlate RNA length with hybridization affinity.

Main Methods:

• Single-molecule fluorescence correlation spectroscopy (FCS) was employed.
• Dissociation constants were measured for RNA single strands of varying lengths (26, 41, and 54 base pairs).
• Translational diffusion coefficients were determined at infinite dilution.

Main Results:

• Dissociation constants for 26 bp, 41 bp, and 54 bp dsRNA were determined as 3.2 nM, 1.4 nM, and 1.0 nM, respectively.
• A model accurately predicted translational diffusion coefficients: D = 4.58 × 10^-10 N^-0.39 m²s^-1.
• Hybridization affinity increases with RNA length.

Conclusions:

• The study provides quantitative single-molecule insights into RNA-RNA hybridization affinity.
• RNA length is a significant factor influencing the stability of double-stranded RNA formation.
• The developed model accurately predicts RNA diffusion, aiding biophysical characterization.