The Translational Coupling Cassette: a tool for evaluating the translation of heterologous proteins in Escherichia coli.

A powerful method for the production of novel metabolites is the expression of heterologous enzymes in a bacterial host. A common challenge when using non-native genes in metabolic engineering is determining if they are being properly expressed. To address this issue, we have constructed a BioFusion-compatible system for testing the translation of a gene of interest. This system couples the translation of the target gene to a fluorescent reporter gene; fluorescence will only be detected when the target gene is entirely translated. This construct enables synthetic biologists to quickly determine if a gene is being expressed without the need for costly antibodies or analytical instruments (e.g. mass spectrometry). Currently, we are utilizing this cassette to optimize the expression of limonene synthase, an enzyme that catalyzes the production of limonene, a monoterpene with potential as a renewable jet fuel.