Nanoscale tools from DNA origami

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Nanoscale tools from DNA origami

Nanoscale tools from DNA origami

8/6/09 9:35 PM

Chemistry World

Nanoscale tools from DNA origami

06 August 2009

US scientists have demonstrated a nanoconstruction approach that allows the creation of selfassembling

DNA 'origami' folded in an array of different shapes, from bent rods to toothed gears.

The researchers say their work opens up new possibilities for engineering nanoscale tools and

devices.

In nature, DNA adopts many different forms but gaining precise control over its shape in synthetic

systems has proved challenging. The new study, led by Hendrik Dietz, now at Technische Universität

München in Germany, shows that targeted changes to the base code can be used to finely tune

the twist and curvature of a bundle of DNA helices.

Importantly, says co-author William Shih of Harvard University, the advance allows scientists to

produce continuously curved structures as opposed to kinked structures. 'I think, with a little bit of

imagination, having control over curvature is actually a fundamental advance in nanofabrication

capability,' he says. 'Imagine if you had a world where you could only build with straight elements -

you would not be able to make a wheel. A more subtle point is that it's very challenging to maintain

rigidity over a kink, which is often a weak point.'

The team's strategy is based on DNA bundles being divided into blocks of regular lengths by

crosslinks between the helices - 'staples'. The staples constrain the shape of the bundles so that

systematically inserting or deleting bases causes the DNA to twist and bend. As Shih explains, the

net effect of adding or removing material is expanding or contracting, the result being that the whole

structure bends to accommodate the change.

The team were able to form many different shapes, including a DNA-origami

bundle bent into a circle with toothed gears

© Science

According to Paul Rothemund, who studies DNA nanostructures at the California Institute of

Technology, the approach is so unexpectedly simple that it could have been worked out in a high

school maths class. 'I thought that it would be several years before we reached the mastery

achieved here and that it might require some serious computer modelling,' he says. 'I think it can

now truly be said that we can make any shape that we desire out of DNA.'

Shih believes that gaining precise control over the structure of DNA will lead to major steps forward

in the development of custom instruments for biology and biophysics. 'We're designing tools on the

nanoscale and an advantage of that is you can use self-assembly and make lots of them, whereas

with optical traps or atomic force microscopy you're basically stuck with one at a time,' he says.

Hao Yan, a bio-nanotechnology specialist at Arizona State University, says the level of quantitative

control over twisting and bending is impressive. He thinks Shih's work could serve as a standard for

creating new types of mechanical DNA and proteins.

Hayley Birch

http://www.rsc.org/chemistryworld/News/2009/August/06080901.asp#

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Nanoscale tools from DNA origami

8/6/09 9:35 PM

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References

H Dietz et al, Science, 2009, 325, 725, DOI: 10.1126/science.1174251

Also of interest

Nano-boxes from DNA origami

06 May 2009

Danish researchers have made a nano-sized box out of DNA that can be opened and

closed in response to 'key' molecules

Colloids twist like DNA

17 September 2008

Magnetic silica dumbbells assemble into chiral helices

Related Links

© Royal Society of Chemistry 2009

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