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Analyzing and Building Nucleic Acid Structures with 3DNA
Published on: April 26, 2013
A-form conformational motifs in ligand-bound DNA structures
1Department of Chemistry, Wright-Rieman Laboratories, Rutgers, the State University of New Jersey, 610 Taylor Road, Piscataway, NJ, 08854-8087, USA.
Journal of Molecular Biology
|July 13, 2000
Summary
Proteins and drugs exploit DNA's conformational flexibility, altering its B-form to A-form. This B-to-A transition, particularly at specific base-pair steps, facilitates enzymatic interactions and DNA bending.
Area of Science:
- Molecular Biology
- Structural Biology
- Biochemistry
Background:
- Proteins and drugs recognize specific DNA sequences through direct interactions and by inducing conformational changes.
- Understanding the sequence-dependent structural code of DNA is crucial for deciphering molecular recognition mechanisms.
Purpose of the Study:
- To analyze the extent of B-to-A conformational conversion at individual base-pair steps in protein and drug-bound DNA crystal complexes.
- To identify ligand-induced conformational changes and understand their role in DNA-ligand interactions.
Main Methods:
- Analysis of DNA crystal complexes using a novel structural parameter (phosphorus atom position) and established measures (torsion angles, base-pair step parameters).
- Comparison of crystallographic findings with solution and fiber data on DNA conformational preferences.
Main Results:
- Identified ligand-induced conformational changes at the base-pair step level, revealing details of the B-DNA to A-DNA conformational pathway.
- Observed that A-DNA conformations in complexes correlate with intrinsic A-forming tendencies of DNA sequences.
- Found that B-to-A transitions often occur in complexes with enzymes involved in DNA processing, exposing specific atoms for enzymatic attack.
Conclusions:
- Proteins and drugs leverage DNA's intrinsic conformational mechanics, particularly the B-to-A transition, for recognition and function.
- The B-to-A conformational change facilitates enzymatic modifications by exposing the phosphodiester linkage and enables DNA bending and groove width modulation.
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