An iron 13S-lipoxygenase with an α-linolenic acid specific hydroperoxidase activity from Fusarium oxysporum

PLoS One. 2013 May 31;8(5):e64919. doi: 10.1371/journal.pone.0064919. Print 2013.

Abstract

Jasmonates constitute a family of lipid-derived signaling molecules that are abundant in higher plants. The biosynthetic pathway leading to plant jasmonates is initiated by 13-lipoxygenase-catalyzed oxygenation of α-linolenic acid into its 13-hydroperoxide derivative. A number of plant pathogenic fungi (e.g. Fusarium oxysporum) are also capable of producing jasmonates, however, by a yet unknown biosynthetic pathway. In a search for lipoxygenase in F. oxysporum, a reverse genetic approach was used and one of two from the genome predicted lipoxygenases (FoxLOX) was cloned. The enzyme was heterologously expressed in E. coli, purified via affinity chromatography, and its reaction mechanism characterized. FoxLOX was found to be a non-heme iron lipoxygenase, which oxidizes C18-polyunsaturated fatty acids to 13S-hydroperoxy derivatives by an antarafacial reaction mechanism where the bis-allylic hydrogen abstraction is the rate-limiting step. With α-linolenic acid as substrate FoxLOX was found to exhibit a multifunctional activity, because the hydroperoxy derivatives formed are further converted to dihydroxy-, keto-, and epoxy alcohol derivatives.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Fatty Acids / chemistry
  • Fatty Acids / metabolism
  • Fusarium / classification
  • Fusarium / genetics
  • Fusarium / metabolism*
  • Hydrogen-Ion Concentration
  • Iron / metabolism*
  • Kinetics
  • Lipoxygenase / chemistry
  • Lipoxygenase / genetics
  • Lipoxygenase / metabolism*
  • Mass Spectrometry
  • Molecular Sequence Data
  • Oxidation-Reduction
  • Phylogeny
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Sequence Alignment

Substances

  • Fatty Acids
  • Recombinant Fusion Proteins
  • Iron
  • 13-lipoxygenase
  • Lipoxygenase

Grant support

This study was financially supported by the DFG in frame of IRTG-1422 and by an ERASMUS grant for ACS. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.