The Early Folding Intermediates of the Tetrahymena Ribozyme are Kinetically Trapped

Area of Science:

• Biophysics
• Molecular Biology
• Biochemistry

Background:

• The RNA folding problem is crucial for understanding biological activity, cellular regulation, and gene therapy.
• RNA folding research, unlike protein folding, is a developing field focusing on tertiary structure stability and kinetics.
• Kinetic traps, hindering efficient folding, have been observed in later stages of Tetrahymena ribozyme folding.

Purpose of the Study:

• To investigate the presence and role of kinetic traps in various steps of Tetrahymena ribozyme folding.
• To extend synchrotron footprinting analysis to probe early folding mechanisms.
• To elucidate the influence of native and nonnative interactions on RNA folding kinetics.

Main Methods:

• Synchrotron footprinting analysis of the Tetrahymena ribozyme.
• Examination of RNA folding rates in the presence of 3M urea.
• Comparative analysis of folding kinetics across different stages.

Main Results:

• Urea treatment significantly increased the folding rates of early steps in ribozyme tertiary structure formation.
• Data supports the hypothesis that the rate-limiting step in Tetrahymena ribozyme folding is a kinetically trapped native interaction.
• Kinetic trapping also impacts earlier folding intermediates, potentially involving nonnative interactions.

Conclusions:

• Kinetic traps are present in multiple stages of Tetrahymena ribozyme folding.
• Both native and nonnative interactions contribute to kinetic barriers in RNA folding.
• Understanding these traps is key to deciphering RNA folding mechanisms and optimizing RNA-based applications.