Magnaporthe oryzae causes rice blast disease and has become a model organism of fungal infections. M. oryzae can oxygenate fatty acids by 7,8-linoleate diol synthase, 10R-dioxygenase-epoxy alcohol synthase, and by a putative manganese lipoxygenase (Mo-MnLOX). The latter two are transcribed during infection. The open reading frame of Mo-MnLOX was deduced from genome and cDNA analysis. Recombinant Mo-MnLOX was expressed in Pichia pastoris and purified to homogeneity. The enzyme contained protein-bound Mn and oxidized 18:2n-6 and 18:3n-3 to 9S-, 11-, and 13R-hydroperoxy metabolites by suprafacial hydrogen abstraction and oxygenation. The 11-hydroperoxides were subject to β-fragmentation with formation of 9S- and 13R-hydroperoxy fatty acids. Oxygen consumption indicated apparent kcat values of 2.8 s(-1) (18:2n-6) and 3.9 s(-1) (18:3n-3), and UV analysis yielded apparent Km values of 8 and 12 μM, respectively, for biosynthesis of cis-trans conjugated metabolites. 9S-Hydroperoxy-10E,12Z,15Z-octadecatrienoic acid was rapidly further oxidized to a triene, 9S,16S-dihydroperoxy-10E,12Z,14E-octadecatrienoic acid. In conclusion, we have expressed, purified and characterized a new MnLOX from M. oryzae. The pathogen likely secretes Mo-MnLOX and phospholipases to generate oxylipins and to oxidize lipid membranes of rice cells and the cuticle.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.abb.2015.07.014 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Antifungal plant flavonoids identified in silico with potential to control rice blast disease caused by Magnaporthe oryzae.
PLoS One
April 2024
Department of Genetic Engineering and Biotechnology, Faculty of Biological Sciences, University of Chittagong, Chattogram, Bangladesh.
Rice blast disease, caused by the fungus Magnaporthe oryzae, poses a severe threat to rice production, particularly in Asia where rice is a staple food. Concerns over fungicide resistance and environmental impact have sparked interest in exploring natural fungicides as potential alternatives. This study aimed to identify highly potent natural fungicides against M.
View Article and Find Full Text PDFDiversity of the manganese lipoxygenase gene family - A mini-review.
Fungal Genet Biol
November 2022
Division of Biochemical Pharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Box 591, SE 751 24 Uppsala, Sweden. Electronic address:
Analyses of fungal genomes of escalate from biological and evolutionary investigations. The biochemical analyses of putative enzymes will inevitably lag behind and only a selection will be characterized. Plant-pathogenic fungi secrete manganese-lipoxygenases (MnLOX), which oxidize unsaturated fatty acids to hydroperoxides to support infection.
View Article and Find Full Text PDFIron and manganese lipoxygenases of plant pathogenic fungi and their role in biosynthesis of jasmonates.
Arch Biochem Biophys
June 2022
Division of Biochemical Pharmacology, Department of Pharmaceutical Biosciences, Uppsala University, Box 591, SE 751 24, Uppsala, Sweden. Electronic address:
Lipoxygenases (LOX) contain catalytic iron (FeLOX), but fungi also produce LOX with catalytic manganese (MnLOX). In this review, the 3D structures and properties of fungal LOX are compared and contrasted along with their associations with pathogenicity. The 3D structures and properties of two MnLOX (Magnaporthe oryzae, Geaumannomyces graminis) and the catalysis of four additional MnLOX have provided information on the metal centre, substrate binding, oxygenation, tentative O channels, and biosynthesis of exclusive hydroperoxides.
View Article and Find Full Text PDFMimicking Elementary Reactions of Manganese Lipoxygenase Using Mn-hydroxo and Mn-alkylperoxo Complexes.
Molecules
November 2021
Department of Chemistry and Center for Environmentally Beneficial Catalysis, The University of Kansas, 1567 Irving Hill Road, Lawrence, KS 66045, USA.
Manganese lipoxygenase (MnLOX) is an enzyme that converts polyunsaturated fatty acids to alkyl hydroperoxides. In proposed mechanisms for this enzyme, the transfer of a hydrogen atom from a substrate C-H bond to an active-site Mn-hydroxo center initiates substrate oxidation. In some proposed mechanisms, the active-site Mn-hydroxo complex is regenerated by the reaction of a Mn-alkylperoxo intermediate with water by a ligand substitution reaction.
View Article and Find Full Text PDFControlling the Reactivity of a Metal-Hydroxo Adduct with a Hydrogen Bond.
J Am Chem Soc
September 2021
The University of Kansas, Department of Chemistry and Center for Environmentally Beneficial Catalysis, 1567 Irving Hill Road, Lawrence, Kansas 66045, United States.
The enzymes manganese lipoxygenase (MnLOX) and manganese superoxide dismutase (MnSOD) utilize mononuclear Mn centers to effect their catalytic reactions. In the oxidized Mn state, the active site of each enzyme contains a hydroxo ligand, and X-ray crystal structures imply a hydrogen bond between this hydroxo ligand and a carboxylate ligand. While hydrogen bonding is a common feature of enzyme active sites, the importance of this particular hydroxo-carboxylate interaction is relatively unexplored.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!