- Number 296 |
- September 28, 2009
3-D DNA crystals: From the molecular to the real world
Researchers created 3-D DNA
structures by using single-stranded
sticky ends that link double helices
in DNA triangles that point in
Using powerful x-rays at two DOE light sources, chemists from New York University and Purdue University have created three-dimensional DNA structures, a breakthrough bridging the molecular world to the world where we live.
DNA's double helices form when single strands of DNA—each containing two pairs of complementary molecular components called bases, attached to a molecular backbone – self-assemble by matching the complementary parts. The researchers added “sticky ends”—small cohesive sequences—to these double helices, forming single-stranded overhangs. Where these overhanging sticky ends are complementary, they bind together to link two double helices. By linking together multiple helices, the researchers form a lattice-like structure that extends in six different directions, thereby yielding a 3-D crystal.
This technique allows researchers to organize more matter and work with it in many more ways than is possible with 2-D crystals.
The crystals were analyzed using x-ray diffraction at Brookhaven National Laboratory’s National Synchrotron Light Source (NSLS) and Argonne National Laboratory’s Advanced Photon Source (APS). Using a variety of detectors, scientists measure how a beam of intense x-rays scatters, or bounces off, the atoms in the sample. The resulting diffraction pattern allows them to reconstruct a 3-D molecular model of the material, showing the positions and relative orientations of the atoms.
“Synchrotron light sources provide powerful tools to investigate a wide variety of biological complexes, including this one,” said Bob Sweet, a biophysicist and leader of the group that runs the NSLS beamline used in the study. “We've been helping these folks for over a dozen years, and they really hit the ball out of the park."
A promising application of this approach is in nanoelectronics, where the enhanced flexibility of 3D components could help manufacturers build parts that are smaller, closer together, and more sophisticated.
The scientists also expect that they can organize biological macromolecules by attaching them to these crystals, which would help in the development of new drugs.The research was supported by grants from the National Institute of General Medical Sciences of the National Institutes of Health, the National Science Foundation, the Army Research Office, the Office of Naval Research, and the W.M. Keck Foundation. The NSLS and APS are supported by the U.S. Department of Energy.
Submitted by DOE's Brookhaven National Laboratory