The highest-resolution images of a single DNA molecule ever captured were taken by a team of scientists, and they show atoms ‘dancing’ as they spin and twist.
Researchers from 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 allows the team to map and observe the movement and position of each individual atom within a single strand of DNA.
Being able to observe DNA in such detail could help accelerate the development of new gene therapies, according to the British team behind the study.
Researchers from the Universities of Sheffield, Leeds and York combined advanced atomic microscopy with supercomputer simulations to create videos of the molecules
The images show in unprecedented detail how the tensions and strains exerted on DNA when it is stuffed into cells can change shape.
Previously, scientists could only see DNA by using microscopes limited to creating static images, video reveals movement of the atoms.
Images are so detailed that it is possible to see the iconic double helix structure of DNA, but when combined with the simulations, the researchers were able to see the position of each individual atom in the DNA and how it spins and twists.
Every human cell contains two meters of DNA, and to fit our cells, it has evolved to spin, twist, and wind itself.
That means loopy DNA is all over the genome, forming twisted structures that exhibit more dynamic behavior than their relaxed counterparts.
The team looked at DNA mini-circuits, which are special because the molecule is connected at both ends to form a loop.
This loop allowed the researchers to give the DNA mini-circles an extra twist, causing the DNA to dance more vigorously.
When the researchers imaged relaxed DNA, without twists and turns, they saw that it did very little.
However, when they gave the DNA an extra twist, it suddenly became much more dynamic and you could see it taking on some very exotic shapes.
These exotic dance moves turned out to be key to finding binding partners for the DNA, because when they take on a wider variety of shapes, a greater variety of other molecules find it attractive.
Images are so detailed that it is possible to see the iconic double helix structure of DNA, but when combined with the simulations, the researchers were able to see the position of each individual atom in the DNA and how it twists and turns.
These exotic dance moves turned out to be key to finding binding partners for the DNA, because when they take a wider range of shapes, a greater variety of other molecules find it attractive.
Previous Stanford research suggested that DNA mini-circuits are potential indicators of health and aging and may act as early markers of disease.
Since the DNA mini-circles can rotate and bend, they can also become very compact.
Being able to study DNA in such detail could accelerate the development of new gene therapies by taking advantage of how twisted and densified DNA circles can work their way into cells.
Dr Alice Pyne, Lecturer in Polymers & Soft Matter at the University of Sheffield, who captured the images, said: ‘Seeing is believing, but with something as small as DNA, seeing the spiral structure of the entire DNA molecule was a huge challenge .
“The videos we’ve developed allow us to observe DNA twisting with an unprecedented level of detail.”
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 such detail could accelerate the development of new gene therapies by taking advantage of how twisted and densified DNA circles can work their way into cells.
Professor Lynn Zechiedrich of Baylor College of Medicine in Houston Texas, USA, who created the DNA mini-circles used in the study, the work was significant.
“They show in remarkable detail how wrinkled, puckered, kinked, denatured and oddly shaped they are that we hope one day will be able to control.”
Dr. Sarah Harris of the University of Leeds, who supervised the study, said the work shows that the laws of physics apply to the miniscule looped DNA as well as to subatomic particles and entire galaxies.
‘We can use supercomputers to understand the physics of twisted DNA. This should help researchers design custom mini-circles for future therapies. ‘
The study, Combining high-resolution atomic force microscopy and molecular dynamics simulations, shows that DNA supercoiling causes kinks and defects that improve flexibility and recognition, has been published in Nature Communications.