Integrated constraints based analysis of an engineered violacein pathway in escherichia coli
| Title | Integrated constraints based analysis of an engineered violacein pathway in escherichia coli |
| Publication Type | Journal Article |
| Year of Publication | 2018 |
| Authors | Immanuel, SRupa Chris, Banerjee, D, Rajankar, MP, Raghunathan, A |
| Journal | Biosystems |
| Volume | 171 |
| Pagination | 10-19 |
| Date Published | SEP |
| Type of Article | Article |
| 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 Delta pgi & Delta pheA 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: Delta pheA SYN: gave the highest violacein titers (33.8 mg/I). Such integrated approaches targeting multiple molecular hierarchies in the cell can be extended further to increase violacein yields. |
| DOI | 10.1016/j.biosystems.2018.06.002 |
| Type of Journal (Indian or Foreign) | Foreign |
| Impact Factor (IF) | 1.619 |
Divison category:
Chemical Engineering & Process Development
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