Meganuclease technologies
The Cellectis meganuclease platform is a product platform
The meganuclease platform is an automated platform designed to generate meganucleases in order to induce site-specific DNA recombination at a chosen natural locus in a living cell. The high-throughput integrated technological platform for screening different meganucleases was designed with the aim of screening for the best potential cutters on a specific target. The activity of each newly created meganuclease is tested using a series of routine standard functional cell based assays developed by Cellectis.
- The cellular trials are carried out on the automated high-throughput screening platform.
Meganucleases do not cut without prior targeted recognition
Meganucleases bind to and cut target DNA sequences of 12 to overs 30 base pairs: the number of possible combinations is therefore somewhere in the region of 70 billion to over 20 trillion. The structure of the largest families of meganucleases shows that they carry out their activity, cutting DNA, at the centre of DNA recognition domains. This original characteristic means that DNA cuts made by meganucleases are highly specific and are entirely reliant on the perfect recognition of the DNA target to be cut. This high degree of specificity is what gives meganucleases the potential to be the ultimate tools for genome surgery in living cells and organisms.
Meganucleases are plastic proteins
Meganucleases adapt to DNA like a key fits into a lock. The target DNA motif is recognized with a high degree of specificity by a set of amino acids directed towards the target DNA and able to adapt perfectly to the DNA motif. If the amino acids of the meganucleases do not adapt to the DNA target, the cut will not take place. Cellectis designs and redefines the amino acids of the meganuclease which play a role in DNA recognition and the functionality of the protein so as to give it a new specificity. The structural analysis of these proteins enables Cellectis to create huge collections of meganuclease variants with specific DNA/protein interactions. This screening of the recombination events induced by meganucleases at a precise site in the DNA is carried out using cell based assays which are analyzed automatically. The results are stored in the Omegabase, Cellectis’ database, and the resulting products are used for all types of genome surgery.
- The collections of meganucleases designed in this way are tested on target DNA in yeasts. Yeasts are placed on filters to characterize the activity of the new meganuclease (a blue yeast demonstrates the activity of a meganuclease). Once validate in yeast each meganuclease is then tested in an automated assay in mammalian cells.
