title: Biosynthesis of the vitamin E compound delta-tocotrienol in recombinant Escherichia coli cells.
abstract: The biosynthesis of natural products in a fast growing and easy to manipulate heterologous host system, such as Escherichia coli, is of increasing interest in biotechnology. This procedure allows the investigation of complex natural product biosynthesis and facilitates the engineering of pathways. Here we describe the cloning and the heterologous expression of tocochromanol (vitamin E) biosynthesis genes in E. coli. Tocochromanols are synthesized solely in photosynthetic organisms (cyanobacteria, algae, and higher green plants). For recombinant tocochromanol biosynthesis, the genes encoding hydroxyphenylpyruvate dioxygenase (hpd), geranylgeranylpyrophosphate synthase (crtE), geranylgeranylpyrophosphate reductase (ggh), homogentisate phytyltransferase (hpt), and tocopherol-cyclase (cyc) were cloned in a stepwise fashion and expressed in E. coli. Recombinant E. coli cells were cultivated and analyzed for tocochromanol compounds and their biosynthesis precursors. The expression of only hpd from Pseudomonas putida or crtE from Pantoea ananatis resulted in the accumulation of 336 mg L(-1) homogentisate and 84 microg L(-1) geranylgeranylpyrophosphate in E. coli cultures. Simultaneous expression of hpd, crtE, and hpt from Synechocystis sp. under the control of single tac-promoter resulted in the production of methyl-6-geranylgeranyl-benzoquinol (67.9 microg g(-1)). Additional expression of the tocopherol cyclase gene vte1 from Arabidopsis thaliana resulted in the novel formation of a vitamin E compound-delta-tocotrienol (15 microg g(-1))-in E. coli.
authors.affiliation: Institute of Microbiology, Universität Stuttgart, Stuttgart, Germany. christoph.albermann@imb.uni-stuttgart.de
authors.forename: Christoph
authors.initials: C
authors.lastname: Albermann
authors.forename: Shashank
authors.initials: S
authors.lastname: Ghanegaonkar
authors.forename: Karin
authors.initials: K
authors.lastname: Lemuth
authors.forename: Tobias
authors.initials: T
authors.lastname: Vallon
authors.forename: Matthias
authors.initials: M
authors.lastname: Reuss
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Armbruster
authors.forename: Georg A
authors.initials: GA
authors.lastname: Sprenger
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D019751:Intramolecular Transferases / Q000378:metabolism; D015394:Molecular Structure; D010957:Plasmids / Q000235:genetics; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000096:biosynthesis / Q000737:chemistry
chemical_list: D011994:Recombinant Proteins; D014810:Vitamin E; C082097:tocotrienol, delta; D019751:Intramolecular Transferases; C103397:tocopherol cyclase