Biosynthesis of bioprivileged, linear molecules via novel carboligase reactions

This proposal seeks to characterize and engineer carbon-carbon (C-C) bond forming transketolases to enable novel biosynthetic pathways to heptane (odd-chain alkane) and suberic acid (C8 di-acid). Many useful fuel and chemical molecules, like heptane and suberic, are difficult to access by petrochemical calalysis. Biosynthesis of these unique molecules mediated by controlled condensations would allow advanced materials, safer solvents, and superior fuels. However, naturally occurring metabolic pathways do not exist for many of these molecules and have been difficult to engineer and control. Our goal is to exploit enzyme substrate promiscuity of transketolases to efficiently form carbon-carbon (C-C) bonds between a-keto acids (e.g., a-ketoglutarate). We will characterize and engineer unique transketolases to synthesize a range of molecules and develop tools to predict and mitigate the toxic consequences of unwanted promiscuous side reactions at the systems level. If successful, we will unlock facile synthesis of a new class of molecules broadly useful in the biofuels and biochemical industry.