PMID: 25489112 , Related PDB ids: 4WWJ, 4WWZ, 4WX0

Authors:

Rui Z, Li X, Zhu X, Liu J, Domigan B, Barr I, Cate JH, Zhang W

Title:

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

Journal:

Proc Natl Acad Sci U S A. 2014 Dec 8. pii: 201419701.

Abstract:

Aliphatic medium-chain 1-alkenes (MCAEs, approximately 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 beta-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.