A team of students from Wageningen University is participating yet again in another edition of the 'international Genetically Engineered Machines' (iGEM) competition. iGEM is a summer science competition between all the universities around the world (including Harvard, MIT, Yale). There is still a vast body of unexplored compounds such as the fungal secondary metabolites that have the potential to
prolong human lifespan. The production of these secondary metabolites in most cases involves a large backbone enzyme that contains multiple catalytic domains. One of the goals is to establish a modular system of domain shuffling to generate a plethora of novel enzymes with new and improved functionalities. The possibilities are endless as there is a myriad of different domains from many fungi. The aim is to transfer the entire lovastatin metabolic pathway from Aspergillus terreus into a GRAS organism like A. One of the main enzymes involved in the production of lovastatin is the 277kDa LovB enzyme, which contains 7 different catalytic domains. Prior studies on this pathway provide a good insight into the catalytic mechanisms of these individual domains. The individual domains have been mapped by sequence analysis and homology modeling. These domains are well defined and often occur in a sequential order, which makes the modular approach more feasible. The rest of the toolkit that is being created, consists of an ATP and a pH biosensor that can be targeted to specific compartments with the use of signal peptides, actin and septa GFP fusions to visualize the cytoskeleton and the junctions between adjacent cells, and chromoproteins that can serve as secondary selection markers. These tools allow one to obtain insight in cellular economy, physiology and architecture, which can be used to optimize the production processes of secondary metabolites.
