DNA Can Fold into Complex Shapes to Execute New Functions
Published:18 Aug.2023 Source:Weill Cornell Medicine
DNA can mimic protein functions by folding into elaborate, three-dimensional structures, according to a study from researchers at Weill Cornell Medicine. The researchers used high-resolution imaging techniques to reveal the novel and complex structure of a DNA molecule they created that mimics the activity of a protein called green fluorescent protein (GFP). GFP, which was derived from jellyfish, has become an important laboratory tool, functioning as a fluorescent tag or beacon in cells.
The findings advance the science of how DNA can be made to fold into complex shapes. DNA in nature exists mostly in a double-stranded, "twisted ladder" or "helical" form, and serves as a relatively stable store of genetic information. All of the other complex biological processes in cells are done by other types of molecules, especially proteins. Last year, Dr. Jaffrey and colleagues reported discovering one such molecule: a single-stranded DNA that folds in a way that allows it to mimic the activity of GFP. The DNA molecule, which Dr. Jaffrey dubbed "lettuce" for the color of its fluorescent emissions
They found that it folds into a shape that has at its center a four-way junction of DNA, of a type never seen before, enclosing the fluorophore in a way that activates it. They also observed that lettuce's foldings are held together with bonds between nucleobases -- the building blocks of DNA that are often referred to as the "letters" in the four-letter DNA alphabet. "What they have discovered is not DNA trying to be like a protein; it's a DNA that is doing what GFP does but in its own special way. Studies like this are going to be essential for the creation of new DNA-based tools