Protein ‘rebar’ could help make error-free nanostructures

DNA is the stuff of life, but it is also the stuff of nanotechnology. Because molecules of DNA with complementary chemical structures recognize and bind to one another, strands of DNA can fit together like Lego blocks to make nanoscale objects of complex shape and structure.

But researchers need to work with much larger assemblages of DNA to realize a key goal: building durable miniature devices such as biosensors and drug-delivery containers. That’s been difficult because long chains of DNA are floppy and the standard method of assembling long chains is prone to error.

Using a DNA-binding protein called RecA as a kind of nanoscale rebar, or reinforcing bar, to support the floppy DNA scaffolding, researchers at the National Institute of Standards and Technology (NIST) have constructed several of the largest rectangular, linear and other shapes ever assembled from DNA. The structures can be two to three times larger than those built using standard DNA self-assembly techniques.

In addition, because the new method requires fewer chemically distinct pieces to build organized structures than the standard technique, known as DNA origami, it is likely to reduce the number of errors in constructing the shapes. That’s a big plus for the effort to produce reliable DNA-based devices in large quantities, said NIST researcher Alex Liddle.