Probing the Flexibility of an Iterative Modular Polyketide Synthase with Non-Native Substrates in Vitro

• DOI: 10.1021/acschembio.8b00422
• Publication Date: 2018-06-18T20:54:10Z
• Authors: Samuel C. Curran; Andrew Hagen; Sean Poust; Leanne Jade G. Chan; Brett M. Garabedian; Tristan de Rond; Marian-Joy Baluyot; Jonathan T. Vu; Andrew K. Lau; Satoshi Yuzawa; Christopher J. Pe...; Leonard Katz; Jay D. Keasling
• Keywords: Polyketide synthase; Branching (polymer chemistry); Protein Engineering; Synthetic Biology

In the search for molecular machinery custom biosynthesis of valuable compounds, modular type I polyketide synthases (PKSs) offer great potential. this study, we investigate flexibility BorM5, iterative fifth module borrelidin synthase, with a panel non-native priming substrates in vitro. BorM5 differentially extends various aliphatic and substituted substrates. Depending on substrate size substitution can exceed three iterations it natively performs. To probe effect methyl branching chain length regulation, engineered variant capable incorporating methylmalonyl- malonyl-CoA into its intermediates. Intermediate methylation did not affect overall length, indicating that enzyme does to count branches specify number iterations. addition providing regulatory insight about produced dozens novel methylated intermediates might be used production hydrocarbons or pharmaceuticals. These findings enable rational engineering recombination inform study other modules.