DNA can be folded into nearly any three-dimensional shape desired with the use of short DNA fragments. The DNA nanostructure can also be equipped with specific docking sites for proteins. A team led by Takashi Morii at the University of Kyoto (Japan) has now introduced a new method for attaching the proteins by means of special “adapters” known as zinc-finger proteins.
The scientists produced rectangular origami structures with several defined cavities. At these locations, the origamis contain various DNA-recognition patterns for different zinc fingers. The researchers then made proteins that contain zinc-finger units at one end and a fluorescing protein or biotin molecule at the other end. Biotin binds specifically to the large protein streptavidin. Atomic force microscopic images show that the streptavidin molecules always bind specifically to the intended cavity in the origami rectangle.
“Our results demonstrate that zinc fingers are suitable site-selective adapters for targeting specific locations within DNA-origami structures,” says Morii. “Several different adapters carrying different proteins can independently bind at defined locations on this type of nanostructure.”
Zinc-finger proteins are convenient and site-selective adaptors for targeting specific locations within DNA-origami structures. Orthogonal targeting of the specific locations in the structures was demonstrated by using two adaptors, and the application of Escherichia coli lysate that contained the adaptor-fused proteins successfully afforded the expected protein–DNA assembly.