title: Microbial biosynthesis of medium-chain 1-alkenes by a nonheme iron oxidase.
abstract: Aliphatic medium-chain 1-alkenes (MCAEs, ∼10 carbons) are "drop-in" compatible next-generation fuels and precursors to commodity chemicals. Mass production of MCAEs from renewable resources holds promise for mitigating dependence on fossil hydrocarbons. An MCAE, such as 1-undecene, is naturally produced by Pseudomonas as a semivolatile metabolite through an unknown biosynthetic pathway. We describe here the discovery of a single gene conserved in Pseudomonas responsible for 1-undecene biosynthesis. The encoded enzyme is able to convert medium-chain fatty acids (C10-C14) into their corresponding terminal olefins using an oxygen-activating, nonheme iron-dependent mechanism. Both biochemical and X-ray crystal structural analyses suggest an unusual mechanism of β-hydrogen abstraction during fatty acid substrate activation. Our discovery unveils previously unidentified chemistry in the nonheme Fe(II) enzyme family, provides an opportunity to explore the biology of 1-undecene in Pseudomonas, and paves the way for tailored bioconversion of renewable raw materials to MCAE-based biofuels and chemical commodities.
authors.affiliation: Energy Biosciences Institute, Departments of Chemical and Biomolecular Engineering.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Rui
authors.affiliation: Energy Biosciences Institute, California Institute for Quantitative Biosciences, and.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: Energy Biosciences Institute, Departments of Chemical and Biomolecular Engineering.
authors.forename: Xuejun
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Energy Biosciences Institute, Bioengineering.
authors.forename: Joyce
authors.initials: J
authors.lastname: Liu
authors.affiliation: Energy Biosciences Institute, Departments of Chemical and Biomolecular Engineering.
authors.forename: Bonnie
authors.initials: B
authors.lastname: Domigan
authors.affiliation: Chemistry, and Molecular and Cell Biology, University of California, Berkeley, CA 94720; and.
authors.forename: Ian
authors.initials: I
authors.lastname: Barr
authors.affiliation: Chemistry, and Molecular and Cell Biology, University of California, Berkeley, CA 94720; and Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720.
authors.forename: Jamie H D
authors.initials: JH
authors.lastname: Cate
authors.affiliation: Energy Biosciences Institute, Departments of Chemical and Biomolecular Engineering, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 wjzhang@berkeley.edu.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Zhang
mesh_terms: D000475:Alkenes / Q000378:metabolism*; D015394:Molecular Structure; D010088:Oxidoreductases / Q000737:chemistry / Q000378:metabolism*; D011549:Pseudomonas / Q000235:genetics
chemical_list: D000475:Alkenes; D010088:Oxidoreductases
keywords: biofuel; biosynthesis; hydrocarbon; iron-dependent desaturase/decarboxylase; terminal olefin