Higher-resolution images of a single DNA molecule never captured have been taken by a team of scientists and show that atoms “dance” as they break and withdraw.
Researchers at the universities of Sheffield, Leeds and York combined advanced atomic microscopy with supercomputer simulations to create videos of the molecules.
The resolution combined with the simulations allow the team to map and observe the motion and position of each atom within a single DNA strand.
Being able to observe DNA in so much detail could help accelerate the development of new gene therapies, according to the British team behind the study.
Researchers at the universities of Sheffield, Leeds and York combined advanced atomic microscopy with supercomputer simulations to create videos of molecules
The images show in unprecedented detail how the strains and strains that are placed in the DNA when piled up inside the cells can change their shape.
Previously, scientists were only able to see DNA by using microscopes that were limited to taking still images, the video reveals the movement of atoms.
The images are so detailed that it is possible to see the iconic double helical structure of DNA, but by combining them with the simulations, the researchers were able to see the position of each atom in the DNA and how it is twisted and removed.
Each human cell contains two meters of DNA and in order to fit inside our cells it has evolved to rotate, rotate and coil.
This means that the deleted DNA is found throughout the genome, forming twisted structures that show a more dynamic behavior than their relaxed counterparts.
The team examined DNA mini-circles, which are special because the molecule joins at both ends to form a loop.
This loop allowed the researchers to give an added twist to the DNA minicircles, making the DNA dance harder.
When the researchers imagined DNA relaxed, without any twists, they saw that it was doing very little.
However, when they gave an added twist to the DNA, it suddenly became much more dynamic and could be seen to take very exotic forms.
These exotic dance movements were found to be the key to finding binding partners for DNA, as when they take on a wider range of shapes, a greater variety of other molecules find it attractive.
The images are so detailed that it is possible to see the iconic double helical structure of DNA, but by combining them with the simulations, the researchers were able to see the position of each atom in the DNA and how it is twisted and removed.
These exotic dance moves were found to be the key to finding binding pairs for DNA, as when they take on a wider range of shapes, a greater variety of other molecules find it attractive.
Previous Stanford research suggested that DNA minicircles are potential indicators of health and aging and may act as early markers of disease.
Because DNA minicircles can rotate and bend, they can also become very compact.
Being able to study DNA in this detail could accelerate the development of new gene therapies by using how twisted and compacted DNA circles can make their way into cells.
Dr. Alice Pyne, a professor of Polymers & Soft Matter at the University of Sheffield, who captured the images, said: “To see is to believe, but with something as small as DNA, to see the helical structure of the whole DNA molecule was extremely difficult.
“The videos we’ve developed allow us to observe DNA deformation with a level of detail never seen before.”
Previous Stanford research suggested that DNA mini-circles are potential indicators of health and aging and may act as early markers of disease.
Being able to study DNA in so much detail could accelerate the development of new gene therapies by using how twisted and compacted DNA circles can make their way into cells.
Professor Lynn Zechiedrich of Baylor College of Medicine in Houston, Texas, USA, who made the DNA mini-circles used in the study significant.
“They show, in remarkable detail, the degree of wrinkles, bubbles, twists, distortions, and strangely that we hope to be able to control someday.”
Dr Sarah Harris of the University of Leeds, who oversaw the research, said the work shows that the laws of physics also apply to small looping DNA as they do to sub-atomic particles and entire galaxies. .
“We can use supercomputers to understand the physics of twisted DNA. This should help researchers design tailor-made mini-circles for future therapies.”
The study, which combines high-resolution atomic force microscopy with molecular dynamics simulations, shows that DNA supercoiling induces flaws and defects that improve flexibility and recognition, is published in Nature Communications.