Conformationally restricted nucleotides as a probe of structure-function relationships in RNA

Area of Science:

• Molecular Biology
• Biochemistry
• Structural Biology

Background:

• RNA molecules perform diverse biological functions.
• The structure and dynamics of RNA, particularly ribose conformation, are crucial for its function.
• Understanding these relationships requires precise experimental tools.

Purpose of the Study:

• To introduce and validate locked nucleic acids (LNAs) as functional probes for RNA analysis.
• To investigate the role of ribose conformation in RNA self-cleavage, stability, and protein recognition.

Main Methods:

• Utilized commercially available locked nucleic acids (LNAs) to modify RNA structures.
• Applied LNA probing to study lead-dependent ribozyme self-cleavage.
• Assessed thermodynamic stability of UUCG tetraloops with LNA modifications.
• Analyzed kinetics of U1A protein recognition by U1 snRNA hairpin II using LNA probes.

Main Results:

• LNA incorporation restricts ribose to C3'-endo (A-form) conformation.
• A single LNA modification in the leadzyme increased catalytic rate 20-fold, suggesting a critical conformational change.
• LNA probing provided functional insights into RNA stability and protein binding kinetics.

Conclusions:

• Locked nucleic acids (LNAs) are versatile probes for analyzing RNA structure-function relationships.
• Ribose conformation plays a critical role in RNA catalytic activity and molecular recognition.
• LNA probing offers a general approach to study the impact of ribose orientation in RNA.