An intelligent Genetically Engineered Slot Machine (iGESM)
The vertebrate immune system produces billions of different antibodies. This diversity is generated by random VDJ-recombination of a limited number of antibody subfragments. This inspired us to construct an automatic recombination system in E. coli that generates large numbers of novel proteins by combinatorial fusion of functional domains. We used the site-specific DNA recombinase Gin of bacteriophage Mu that depends on the presence of a DNA enhancer element for efficient recombination. This allowed us to construct a system, called “The Recombinator”, which automatically shuts down after successful recombination. We visualized the randomizing function of our genetically engineered slot machine by combining fluorescent colors with cellular localization domains. By scaling up the number of recombination modules and functional domains our system will be able to generate a multitude of new proteins. We envision that “The Recombinator” will serve as a tool to create novel enzymatic activities for innovative drug design, environmental detoxification and metabolic engineering.
As proof-of-principle of our recombinator system we created combinatorial fusions of bacterial intracellular localization domains with different fluorescent proteins. We expected to generate a mixture of bacteria that glow in different colors and at different positions in all possible combinations.
Here, we have dealt only with few modules, but with additional recombination modules, the number of possible combinations raises exponentially.