Team:Evry Paris-Saclay

Evry-Saclay 2021 iGEM team website

Proteins Directed Evolution

Evolution.T7: Targeted and modular double-stranded in vivo mutagenesis using RNA polymerase-guided cytosine and adenine deaminases

Every life form has emerged through evolution. Successive random mutations followed by selection of the fittest individuals has resulted in vastly complex and diverse living organisms. This process can be accelerated in the laboratory to create new protein variants with desirable properties by diversification of a known DNA sequence followed by selective amplification, an approach known as directed evolution.
In vivo diversification with locus-specific targeting has recently become possible using T7 RNA polymerase-guided deaminases. Here, aiming to maximize the effectiveness of this method, we have combined two strategies. First, we use new cytosine and adenine deaminases with improved mutagenesis rates. Second, our innovative design can target both DNA strands simultaneously, resulting in improved diversification and reducing the bias observed in existing systems that mainly target only one of the strands of DNA in each mutation cycle. Finally, we validate the performance of our system by evolving enzymes, fluorescent proteins, and transcription factors.

Watch our Presentation Video to learn more about the story behind Evolution.T7


The 2D particles animations visible at the top of the page represent structures evolving on their own and taking different shapes. The users are able to interact with them using their mouses cursors, consequently orienting their evolution. This animation is a metaphor for the directed evolution of molecules, like proteins, which is the heart of our project.