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Analyzing and Building Nucleic Acid Structures with 3DNA
Published on: April 26, 2013
1H-1H correlations across N-H...N hydrogen bonds in nucleic acids
A Majumdar1, Y Gosser, D J Patel
1Cellular Biochemistry and Biophysics Department, Memorial Sloan-Kettering Cancer Center, New York 10021, USA. majumdar@sbnmr1.mskcc.org
Journal of Biomolecular NMR
|February 5, 2002
Summary
New NMR methods directly correlate protons across nucleic acid hydrogen bonds, simplifying structural analysis. These 1H-1H correlations bypass difficult nitrogen assignments, improving studies of RNA and DNA structures.
Area of Science:
- Structural Biology
- Nuclear Magnetic Resonance (NMR) Spectroscopy
- Biophysics
Background:
- Assigning receptor nitrogen atoms is crucial for identifying hydrogen bonds in nucleic acids using 2-Dimensional Heteronuclear (2HJ(NN)-COSY) Nuclear Magnetic Resonance (NMR) experiments.
- Poor dispersion of nitrogen resonances complicates nitrogen assignment, hindering unambiguous hydrogen bond identification.
Purpose of the Study:
- To develop novel Nuclear Magnetic Resonance (NMR) pulse sequences for direct internucleotide proton-proton correlations across Nd...HNa hydrogen bonds in nucleic acids.
- To circumvent the need for nitrogen resonance assignment and overcome issues related to poor nitrogen resonance dispersion.
Main Methods:
- Development and application of specific 1H-1H correlation pulse sequences: H2(N1N3)H3, H5(N3N1)H1/H6(N3N1)H1, and H2(N2N7)H8.
- Utilizing uniformly 13C/15N labeled nucleic acid samples for Nuclear Magnetic Resonance (NMR) analysis.
- Demonstration on diverse biological systems including RNA regulatory elements, DNA G-quadruplexes, and peptide-RNA complexes.
Main Results:
- Successfully established direct 1H-1H connectivities across various base pairs (Watson-Crick A-U, G-C; mismatched G.A, G.G, A.A).
- The new pulse sequences effectively bypass the requirement for donor/acceptor nitrogen assignment.
- Demonstrated the utility of the methodology on complex biological macromolecules like HIV-1 TAR RNA, G-quadruplex DNA, and peptide-RNA complexes.
Conclusions:
- The presented 1H-1H correlation strategies provide a robust alternative for analyzing hydrogen bonds in nucleic acids.
- This methodology simplifies structural determination by avoiding challenging nitrogen resonance assignments.
- The approach enhances the study of nucleic acid structure and function in various biological contexts.
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