title: Engineering dynamic pathway regulation using stress-response promoters.
abstract: Heterologous pathways used in metabolic engineering may produce intermediates toxic to the cell. Dynamic control of pathway enzymes could prevent the accumulation of these metabolites, but such a strategy requires sensors, which are largely unknown, that can detect and respond to the metabolite. Here we applied whole-genome transcript arrays to identify promoters that respond to the accumulation of toxic intermediates, and then used these promoters to control accumulation of the intermediate and improve the final titers of a desired product. We apply this approach to regulate farnesyl pyrophosphate (FPP) production in the isoprenoid biosynthetic pathway in Escherichia coli. This strategy improved production of amorphadiene, the final product, by twofold over that from inducible or constitutive promoters, eliminated the need for expensive inducers, reduced acetate accumulation and improved growth. We extended this approach to another toxic intermediate to demonstrate the broad utility of identifying novel sensor-regulator systems for dynamic regulation.
authors.affiliation: 1] Joint BioEnergy Institute, Emeryville, California, USA. [2] Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, USA. [3] Department of Chemical & Biomolecular Engineering, University of California, Berkeley, California, USA.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Dahl
authors.forename: Fuzhong
authors.initials: F
authors.lastname: Zhang
authors.forename: Jorge
authors.initials: J
authors.lastname: Alonso-Gutierrez
authors.forename: Edward
authors.initials: E
authors.lastname: Baidoo
authors.forename: Tanveer S
authors.initials: TS
authors.lastname: Batth
authors.forename: Alyssa M
authors.initials: AM
authors.lastname: Redding-Johanson
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Petzold
authors.forename: Aindrila
authors.initials: A
authors.lastname: Mukhopadhyay
authors.forename: Taek Soon
authors.initials: TS
authors.lastname: Lee
authors.forename: Paul D
authors.initials: PD
authors.lastname: Adams
authors.forename: Jay D
authors.initials: JD
authors.lastname: Keasling
mesh_terms: D016000:Cluster Analysis; D004926:Escherichia coli / Q000235:genetics / Q000502:physiology; D029968:Escherichia coli Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism; D020869:Gene Expression Profiling / Q000379:methods*; D060847:Metabolic Engineering / Q000379:methods*; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D000081223:Polycyclic Sesquiterpenes; D011106:Polyisoprenyl Phosphates; D012717:Sesquiterpenes / Q000378:metabolism; D013312:Stress, Physiological / Q000235:genetics*; D049490:Systems Biology / Q000379:methods*
chemical_list: D029968:Escherichia coli Proteins; D000081223:Polycyclic Sesquiterpenes; D011106:Polyisoprenyl Phosphates; D012717:Sesquiterpenes; C515348:amorpha-4,11-diene; C004808:farnesyl pyrophosphate