Researchers directly visualize DNA strands pairing via metal ion bridges for first time
Scientists used atomic force microscopy to capture two DNA molecules aligning groove-to-groove, with positively charged metal ions bridging the gap.
Researchers from the University of York, Imperial College London and the University of Sheffield employed atomic force microscopy to obtain high-resolution images of two short DNA fragments aligning groove-to-groove. Complementary simulations revealed that positively charged divalent metal ions occupy the DNA grooves and form bridges that offset electrostatic repulsion, allowing the strands to zip together. The observations validate the “DNA zipper” hypothesis proposed about twenty years ago by Alexey Kornyshev’s group.
The study also found that certain DNA sequences create stronger contacts, forming hotspots that could influence genetic recombination, gene silencing and cancer development. Co-lead authors Agnes Noy and Thomas Catley noted the findings may help pinpoint genome regions involved in DNA pairing and inspire new biotechnological applications. The results were published in Nucleic Acids Research.
Why it matters
Seeing how DNA overcomes charge repulsion clarifies key genetic processes and could advance cancer research and biotech design.
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