A few years ago, CRISPR technology was a huge breakthrough in science. It allows scientists to cut double-stranded DNA, making modifying specific genes in plants, animals, and humans easier. This tool has become key in developing treatments for various diseases.
Recently, Professor Frédéric Veyrier and his team at the Institut national de la recherche scientifique (INRS) developed a new tool using enzymes called Ssn, which can make precise cuts in single-stranded DNA.
Single-stranded DNA is less common than double-stranded DNA but plays a vital role in cell replication and repair processes. It’s also used in many technologies, including gene editing, molecular diagnostics, and nanotechnology.
Until now, no enzyme has been known to exclusively target single-stranded DNA sequences, which has limited the development of technologies based on this type of DNA.
Scientists discovered thousands of rare new CRISPR systems
For the first time, Professor Veyrier and his team at INRS have discovered a family of enzymes that can cut specific sequences in single-stranded DNA. These enzymes, called site-specific single-stranded nucleases (Ssn), have unique properties that allow them to cleave single-stranded DNA.
The team first identified these endonucleases as part of the GIY-YIG superfamily. They focused on one specific enzyme found in Neisseria meningitidis (the bacterium that causes meningitis), which plays a key role in the exchange and modification of genetic material, driving evolution.
While studying the enzyme, researchers found that it recognizes a specific DNA sequence frequently appearing in the Neisseria meningitidis genome. This sequence plays a crucial role in the bacterium’s natural transformation process, influencing how its genome changes.
The researchers also discovered thousands of similar enzymes that can specifically target and cut their own single-stranded DNA sequence. This means that a wide variety of enzymes share this unique property, each with its own specificity.
New four-stranded structure that comes and goes in the DNA
These findings open up new possibilities for DNA recognition and manipulation. They could lead to breakthroughs in both biology and medicine, offering better ways to control bacteria and manage infections linked to them.
On the other hand, the discovery of enzymes specifically targeting single-stranded DNA opens up new opportunities for more precise and efficient genetic manipulation tools. These enzymes could improve gene editing techniques, enhance DNA detection, and refine molecular diagnostic tools. They also have potential uses in medical and industrial fields, including pathogen detection and genetic manipulation for therapies and treatments.
These advances offer great promise in tackling various health challenges. Currently, a patent is pending for the results of this groundbreaking work.
Journal Reference:
- Chenal, M., Rivera-Millot, A., Harrison, L.B. et al. Discovery of the widespread site-specific single-stranded nuclease family Ssn. Nat Commun 16, 2388 (2025). DOI: 10.1038/s41467-025-57514-1
Source: Tech Explorist