Characterizing hydrogen bonds in intact RNA from MS2 bacteriophage using magic angle spinning NMR

Area of Science:

• Biochemistry
• Structural Biology
• Biophysics

Background:

• RNA molecules are crucial for numerous biological processes.
• Understanding RNA structure is essential for elucidating its function.
• Secondary RNA structures are stabilized by hydrogen bonds between base pairs.

Purpose of the Study:

• To present an advanced methodology for studying large, intact RNA biomolecules.
• To characterize hydrogen-bond contacts within RNA using nuclear magnetic resonance (NMR) spectroscopy.
• To improve the analysis of RNA secondary structures.

Main Methods:

• Utilized homonuclear 15N solid-state NMR spectroscopy.
• Employed proton-driven spin-diffusion experiments with extended mixing times (up to 16 s).
• Incorporated multiple rotor-synchronous 1H inversion pulses (radio-frequency dipolar recoupling) to enhance signal detection.

Main Results:

• Successfully identified key hydrogen-bond contacts in full-length MS2 phage RNA.
• Observed dominant guanine-cytosine Watson-Crick basepairs and significant guanine-uracil wobble basepairs.
• Differentiated between basepaired and non-basepaired nitrogen atoms within the RNA structure.

Conclusions:

• The improved solid-state NMR technique facilitates the characterization of hydrogen-bond types in large, intact RNA.
• This method can guide RNA secondary structure prediction and determination.
• Provides valuable insights into the structural basis of RNA function.