title: The versatility of the fungal cytochrome P450 monooxygenase system is instrumental in xenobiotic detoxification.
abstract: Cytochromes P450 (CYPs) catalyse diverse reactions and are key enzymes in fungal primary and secondary metabolism, and xenobiotic detoxification. CYP enzymatic properties and substrate specificity determine the reaction outcome. However, CYP-mediated reactions may also be influenced by their redox partners. Filamentous fungi with numerous CYPs often possess multiple microsomal redox partners, cytochrome P450 reductases (CPRs). In the plant pathogenic ascomycete Cochliobolus lunatus we recently identified two CPR paralogues, CPR1 and CPR2. Our objective was to functionally characterize two endogenous fungal cytochrome P450 systems and elucidate the putative physiological roles of CPR1 and CPR2. We reconstituted both CPRs with CYP53A15, or benzoate 4-hydroxylase from C. lunatus, which is crucial in the detoxification of phenolic plant defence compounds. Biochemical characterization using RP-HPLC shows that both redox partners support CYP activity, but with different product specificities. When reconstituted with CPR1, CYP53A15 converts benzoic acid to 4-hydroxybenzoic acid, and 3-methoxybenzoic acid to 3-hydroxybenzoic acid. However, when the redox partner is CPR2, both substrates are converted to 3,4-dihydroxybenzoic acid. Deletion mutants and gene expression in mycelia grown on media with inhibitors indicate that CPR1 is important in primary metabolism, whereas CPR2 plays a role in xenobiotic detoxification.
authors.affiliation: National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana, Slovenia. ljerka.lah@ki.si
authors.forename: Ljerka
authors.initials: L
authors.lastname: Lah
authors.forename: Barbara
authors.initials: B
authors.lastname: Podobnik
authors.forename: Metka
authors.initials: M
authors.lastname: Novak
authors.forename: Branka
authors.initials: B
authors.lastname: Korošec
authors.forename: Sabina
authors.initials: S
authors.lastname: Berne
authors.forename: Matjaž
authors.initials: M
authors.lastname: Vogelsang
authors.forename: Nada
authors.initials: N
authors.lastname: Kraševec
authors.forename: Neja
authors.initials: N
authors.lastname: Zupanec
authors.forename: Jure
authors.initials: J
authors.lastname: Stojan
authors.forename: Joerg
authors.initials: J
authors.lastname: Bohlmann
authors.forename: Radovan
authors.initials: R
authors.lastname: Komel
mesh_terms: D000595:Amino Acid Sequence; D001203:Ascomycota / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D050565:Benzoate 4-Monooxygenase / Q000378:metabolism; D019817:Benzoic Acid / Q000378:metabolism; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D005658:Fungi / Q000378:metabolism; D062385:Hydroxybenzoates / Q000032:analysis; D050216:Metabolic Detoxication, Phase I / Q000235:genetics / Q000502:physiology*; D009251:NADPH-Ferrihemoprotein Reductase / Q000235:genetics / Q000378:metabolism*; D010226:Parabens / Q000032:analysis; D017384:Sequence Deletion; D014641:Vanillic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D015262:Xenobiotics / Q000378:metabolism*
chemical_list: D062385:Hydroxybenzoates; D010226:Parabens; D015262:Xenobiotics; C032948:3-hydroxybenzoic acid; C009091:protocatechuic acid; D019817:Benzoic Acid; D003577:Cytochrome P-450 Enzyme System; C056267:3-methoxybenzoic acid; D050565:Benzoate 4-Monooxygenase; D009251:NADPH-Ferrihemoprotein Reductase; D014641:Vanillic Acid; C038193:4-hydroxybenzoic acid