Researchers observe DNA strands zipping together via metal ion bridges

Researchers have successfully observed the mechanism by which two negatively charged DNA strands overcome mutual electrical repulsion to “zip” together. Using high-powered atomic force microscopy and advanced computer simulations, a team from the University of York and the University of Sheffield visualized short DNA fragments aligning with precision, groove for groove.

The study revealed that positively charged metal ions act as molecular bridges. These ions settle into the grooves of the DNA, neutralizing the repulsion and allowing the strands to lock together. This finding provides direct visual evidence for the “DNA zipper” model, a theory proposed approximately 20 years ago.

Understanding this ion-mediated pairing is critical for studying fundamental biological processes, including genetic recombination, gene silencing, and DNA repair. Scientists noted that identifying regions of the genome specifically involved in this pairing could help researchers understand how mutations disrupt cellular processes and contribute to the development of cancer.