Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8406354 | Biosystems | 2018 | 10 Pages |
Abstract
Strategies towards optimal violacein biosynthesis, a potential drug molecule, need systems level coordination of enzymatic activities of individual genes in a multigene operon vioABCDE. Constraints-based flux balance analysis of an extended iAF1260 model (iAF1260vio) with a reconstructed violacein module predicted growth and violacein yields in Escherichia coli accurately. Shadow price (SP) analysis identified tryptophan metabolism and NADPH as limiting. Increased tryptophan levels in Îpgi & ÎpheA were validated using in silico gene deletion analysis. Phenotypic phase plane (PhPP) analysis highlighted sensitivity between tryptophan and NADPH for violacein synthesis at molar growth yields. A synthetic VioABCDE operon (SYNO) sequence was designed to maximize Codon Adaptive Index (CAI: 0.9) and tune translation initiation rates (TIR: 2-50 fold higher) in E. coli. All pSYN E. coli transformants produced higher violacein, with a maximum six-fold increase in yields. The rational design E. coli: ÎpheA SYN: gave the highest violacein titers (33.8â¯mg/l). Such integrated approaches targeting multiple molecular hierarchies in the cell can be extended further to increase violacein yields.
Related Topics
Physical Sciences and Engineering
Mathematics
Modelling and Simulation
Authors
Selva Rupa Christinal Immanuel, Deepanwita Banerjee, Mayooreshwar P. Rajankar, Anu Raghunathan,