The highest resolution images of a single DNA molecule ever captured were made by a team of scientists and show the atoms “dancing” as they twist and twist.
Researchers at the universities of Sheffield, Leeds and York have combined advanced atomic microscopy with supercomputer simulations to create videos of molecules.
The resolution, combined with the simulations, allows the team to harass and observe the motion and position of each atom in a single strand of DNA.
Being able to observe such detailed DNA 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 have combined advanced atomic microscopy with supercomputer simulations to create videos of molecules
The images show in unprecedented detail how the strains and strains placed on the DNA when crammed inside the cells can change shape.
Previously, scientists could only see DNA using microscopes that were limited to taking still images, with the videos revealing the motion of atoms.
The images are so detailed that it is possible to see the iconic double helical structure of DNA, but when combined with simulations, the researchers were able to see the position of each atom in DNA and how it twists and contorts.
Every human cell contains two meters of DNA and to fit into our cells it has evolved to twist, turn and wrap.
This means that loopy DNA is everywhere in the genome, forming twisted structures that exhibit more dynamic behavior than their relaxed counterparts.
The team looked at DNA minicircles, which are special because the molecule is joined at both ends to form a loop.
This loop allowed the researchers to give the DNA minicircles an extra twist, making the DNA dance more energetically.
When the researchers imagined DNA relaxed, without any twisting, they saw that it did very little.
However, when they gave the DNA an extra twist, it suddenly became much more dynamic and could be seen to take on some very exotic shapes.
These exotic dance movements have proven to be the key to finding DNA binding partners, because when they take on a wider range of shapes, then 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 when combined with simulations, the researchers were able to see the position of each atom in DNA and how it twists and contorts.
These exotic dance moves have proven to be the key to finding DNA binding partners, because when they take on a wider range of shapes, then a greater variety of other molecules find it attractive.
Previous research at Stanford has suggested that DNA minicircles are potential indicators of health and aging and may act as early markers for disease.
Because DNA minicircles can twist and bend, they can also become very compact.
The ability to study DNA in such 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 lecturer on polymers and soft materials at the University of Sheffield, who captured the footage, said: “To see is to believe, but with something as small as DNA, he saw the helical structure of the whole DNA molecule was extremely difficult.
“The videos we have developed allow us to observe the twisting of DNA to a level of detail that has never been seen before.”
Previous Stanford research has suggested that DNA minicircles are potential indicators of health and aging and may act as early markers of disease.
The ability to study DNA in such detail could accelerate the development of new gene therapies by using the way twisted and compacted DNA circles can make their way into cells.
Professor Lynn Zechiedrich of Baylor College of Medicine in Houston, Texas, USA, who performed the DNA mini-circles used in the study, the work was significant.
“They show, in remarkable detail, how wrinkled, boiling, bent, distorted and strangely shaped they are, which we hope to be able to control one day.”
Dr. Sarah Harris of the University of Leeds, who oversaw the research, said the paper shows that the laws of physics apply to small curly DNA, as well as subatomic particles and entire galaxies.
“We can use supercomputers to understand the physics of twisted DNA. This should help researchers design customized mini-circles for future therapies.
The study, combining high-resolution atomic force microscopy with molecular dynamics simulations shows that DNA overwrapping induces bends and defects that increase flexibility and recognition, is published in Nature Communications.