Probing RNA Structures and Interactions Using Fluorescence Lifetime Analyses.

Area of Science:

• Biochemistry
• Molecular Biology
• Structural Biology

Background:

• Analyzing the structure of large, complex noncoding RNAs remains challenging.
• Fluorescent probes like 2-aminopurine (2AP) and pyrrolo-cytosine (PyC) provide insights into local RNA structure, dynamics, and interactions.
• Current methods often rely on fluorescence intensity, which can be less informative.

Purpose of the Study:

• To develop and benchmark a protocol correlating local RNA conformations with fluorescence lifetimes.
• To establish fluorescence lifetime measurements as a superior technique for RNA structural analysis.
• To demonstrate the broad applicability of this method across various RNA systems.

Main Methods:

• Site-specific incorporation of fluorescent probes (2AP, PyC) into RNA molecules.
• Measurement of fluorescence lifetimes associated with specific local RNA conformations.
• Benchmarking and correlation of fluorescence lifetime data with known structural states.

Main Results:

• Developed a protocol linking local RNA conformations to fluorescence lifetimes.
• Demonstrated that fluorescence lifetimes are more sensitive to local RNA structures than sequence context.
• Established fluorescence lifetime measurements as a powerful alternative to intensity-based methods.

Conclusions:

• Fluorescence lifetime measurements provide a sensitive and generalizable method for probing local RNA structure and dynamics.
• This technique offers significant advantages over traditional fluorescence intensity-based approaches.
• The method has broad utility for studying diverse RNA and ribonucleoprotein complexes.