Microbial biosynthesis of medium-chain 1-alkenes by a nonheme iron oxidase

Proc Natl Acad Sci U S A. 2014 Dec 23;111(51):18237-42. doi: 10.1073/pnas.1419701112. Epub 2014 Dec 8.


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.

Keywords: biofuel; biosynthesis; hydrocarbon; iron-dependent desaturase/decarboxylase; terminal olefin.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkenes / metabolism*
  • Molecular Structure
  • Oxidoreductases / chemistry
  • Oxidoreductases / metabolism*
  • Pseudomonas / genetics


  • Alkenes
  • Oxidoreductases

Associated data

  • PDB/4WWJ
  • PDB/4WWZ
  • PDB/4WX0