One of the most fundamental parts of the human genome is deoxyribonucleic acid, more commonly known as DNA. DNA essentially contains the guidelines needed for the development of an organism, establishing it as an utmost necessity for the continuation of life. What most people don’t necessarily know as well is that DNA naturally carries a negative charge.
Following general electrostatics, two objects with similar charges should repel each other. DNA, however, occasionally needs to join together for major processes such as genetic recombination, gene splicing, and, more negatively, cancer development. So how does such a process happen? Professor Agnes Noy and her team at the University of York witnessed the answer to this question when they watched two DNA pieces align with utmost precision.
These fragments connected groove for groove, but how? Powerful computer simulations revealed that this was the work of positively charged metal ions appearing in between, serving as connection points between the two pieces.
Professor Noy describes the discovery of such a process as one that “could help researchers identify regions of the genome specifically involved in DNA pairing.” DNA pairing is a crucial aspect of the human genome as it consistently allows DNA to be transcribed into RNA and later into amino acids. Additionally, this could have big implications for the advancement of gene repair in cells, plants and mammals alike.
This process, now physically observed, provides crucial experimental evidence towards the electrostatic DNA zipper, presented 20 years ago by Professor Alexey Kornyshev of Imperial College London. The basis of this idea revolves around discussing the effect of gathering ions on DNA’s electrical landscape. Specifically, as a direct result of DNA’s helical nature, these ionic charges are hypothesized to create a recurring pattern enabling helices to connect together.
The researchers investigated this process by scanning DNA via atomic force microscopy, which is a technique developed to scan microscopic surfaces and generate incredibly high-resolution 3D topographic maps. In turn, this allowed the researchers to analyze how the DNA molecules were positioned.
In tandem with this, advanced computer simulations and algorithms traced the behavior of individual atoms and molecules. The simulations revealed that dual-charged metallic ions effectively act as a bridge, interacting with both DNA molecules and keeping them in alignment.
Dr. Thomas Catley of the University of Sheffield described it as “incredible to be able to directly visualize the long-hypothesized mechanism for the first time,” adding that these discoveries may illuminate deeper implications in multiple cellular processes. Dr. Victor Velasco-Berrelleza of the University of Sheffield added that “the simulations allow us to uncover the molecular mechanism behind [the DNA interactions].”
Furthermore, the researchers discovered that the DNA does not automatically pair equally with every sequence, with some DNA strands creating far stronger contacts than others. Something similar was seen in another recent finding where researchers found that matching DNA sequences align more frequently than nonmatching sequences.
Moving forward, these discoveries could hold major uses in numerous fields, including the likes of medicine, biology, and even technology. Findings like these pave the path forward for the frontier of humanity.
