Final Report Summary - MINT ENZYMES (Microbial Expression Platform for Membrane Integrated Enzymes)
At the core of biotechnology is heterologous expression of proteins, i.e. to transfer genes into foreign hosts like microorganisms for protein production. One of the key challenges in protein production relates to the degeneracy of the genetic code. Membrane integrated (MINT) proteins and enzymes perform crucial tasks in living organisms and are prime drug targets, but are difficult to produce in their fully functional state due to their hydrophobic character. Our long-term goal is to learn how the DNA code affects folding of membrane proteins and how to recode them for better production in microorganisms. In the first two years of the MINT enzymes project we have successfully optimized the expression of two membrane transporters by introducing synonymous mutations on the 5´end o their coding sequences. Additionally we have constructed variants of tRNA over-expressing plasmids for studying the effect of codon usage in microbial cell factories. Finally we engineered E. coli for high-level production of precursors of the medically important diterpene forskolin. In the last two years of the project we have contributed with the development of synthetic biology tools for cell factory engineering.