Related Experiment Videos
How sequence defines structure: a crystallographic map of DNA structure and conformation
Franklin A Hays1, Amy Teegarden, Zebulon J R Jones
1Department of Biochemistry and Biophysics, Oregon State University, Agricultural and Life Sciences Building 2011, Corvallis, OR 97331-7305, USA.
Summary
Researchers mapped DNA structures by crystallizing nearly all sequence permutations of a specific DNA motif. This reveals how DNA sequence dictates its three-dimensional conformation, including B-DNA, A-DNA, and Holliday junctions.
Area of Science:
- Structural biology
- Molecular genetics
- Biochemistry
Background:
- Understanding DNA sequence's role in its 3D structure is fundamental.
- Previous studies have explored DNA conformation but lacked comprehensive sequence-structure mapping.
Purpose of the Study:
- To determine how specific DNA sequences dictate macromolecular conformation.
- To create a comprehensive map of DNA structures based on sequence variations.
Main Methods:
- Crystallographic screening of 63 of 64 permutations of the DNA sequence d(CCnnnN6N7N8GG).
- Integration of existing structural data to build a dataset of 37 single-crystal structures.
- Analysis of amphimorphic sequences that adopt multiple conformations.
Main Results:
- Successfully crystallized 63 out of 64 sequence permutations.
- Assembled a dataset encompassing three major DNA structural classes: B-DNA, A-DNA, and Holliday junctions.
- Identified amphimorphic sequences bridging different structural phases and enabling detailed analysis of sequence-induced conformational changes.
Conclusions:
- Established a detailed map of DNA structures, navigable by single nucleotide steps.
- Dissected the stabilization and conformational variations within DNA structural classes based on sequence.
- Differentiated sequence-driven conformational changes from crystal or crystallization artifacts.