title: A novel class of fungal lipoxygenases.
abstract: Lipoxygenases (LOXs) are well-studied enzymes in plants and mammals. However, fungal LOXs are less studied. In this study, we have compared fungal LOX protein sequences to all known characterized LOXs. For this, a script was written using Shell commands to extract sequences from the NCBI database and to align the sequences obtained using Multiple Sequence Comparison by Log-Expectation. We constructed a phylogenetic tree with the use of Quicktree to visualize the relation of fungal LOXs towards other LOXs. These sequences were analyzed with respect to the signal sequence, C-terminal amino acid, the stereochemistry of the formed oxylipin, and the metal ion cofactor usage. This study shows fungal LOXs are divided into two groups, the Ile- and the Val-groups. The Ile-group has a conserved WRYAK sequence that appears to be characteristic for fungal LOXs and has as a C-terminal amino acid Ile. The Val-group has a highly conserved WL-L/F-AK sequence that is also found in LOXs of plant and animal origin. We found that fungal LOXs with this conserved sequence have a Val at the C-terminus in contrast to other LOXs of fungal origin. Also, these LOXs have signal sequences implying these LOXs will be expressed extracellularly. Our results show that in this group, in addition to the Gaeumannomyces graminis and the Magnaporthe salvinii LOXs, the Aspergillus fumigatus LOX uses manganese as a cofactor.
authors.affiliation: Laboratory of Systems and Synthetic Biology, Microbial Systems Biology, Wageningen University, Dreijenplein 10, 6703 HB, Wageningen, The Netherlands, ruud.heshof@wur.nl.
authors.forename: Ruud
authors.initials: R
authors.lastname: Heshof
authors.forename: Sirpa
authors.initials: S
authors.lastname: Jylhä
authors.forename: Thomas
authors.initials: T
authors.lastname: Haarmann
authors.forename: Ann Louise Worsøe
authors.initials: AL
authors.lastname: Jørgensen
authors.forename: Trine Kastrup
authors.initials: TK
authors.lastname: Dalsgaard
authors.forename: Leo H
authors.initials: LH
authors.lastname: de Graaff
mesh_terms: D020816:Amino Acid Motifs; D019295:Computational Biology / Q000379:methods; D017124:Conserved Sequence; D005658:Fungi / Q000201:enzymology* / Q000235:genetics*; D058945:Lipoxygenases / Q000235:genetics*; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid
chemical_list: D058945:Lipoxygenases