Comparative functional characterization of a novel benzoate hydroxylase cytochrome P450 of Fusarium oxysporum

• FoCYP53A19 from Fusarium oxysporum was identified, cloned and heterologously expressed in S. cerevisiae.
• Functional characterization of FoCYP53A19 with the heterologous and homologous cytochrome P450 reductases (CPR).
• Catalytic efficiency and substrate specificity of FoCYP53A19 were significantly influenced and altered by the source of CPR.
• FoCYP53A19 with F. oxysporum CPR showed reactivity toward benzoic acid, 3-methoxybenzoic acid and 3-hydroxybenzoic acid.
• Two-fold advantages of FoCYP53A19 with F. oxysporum CPR are higher product conversion rate and broader substrate specificity.

FoCYP53A19, a novel cytochrome P450 capable of performing benzoate hydroxylation, was identified and characterized from the ascomycete Fusarium oxysporum f.sp. lycopersici. Comparative functional analysis of FoCYP53A19 with the heterologous and homologous cytochrome P450 reductases (CPR) such as Saccharomyces cerevisiae (ScCPR), Candida albicans (CaCPR) and F. oxysporum (FoCPR) revealed novel catalytic properties. The catalytic efficiency and substrate specificity of FoCYP53A19 were significantly influenced and altered by the source of the reductase employed. The yeast reconstitution system of FoCYP53A19 with ScCPR performed the hydroxylation of benzoic acid (BA) and demethylation of 3-methoxybenzoic acid (3-MBA); but when reconstituted with CaCPR, FoCYP53A19 performed only the essential hydroxylation of fungal benzoate catabolism. Remarkably, FoCYP53A19 with its homologous reductase FoCPR, not only demonstrated the improved conversion rates of BA and 3-MBA, but also exhibited activity toward the hydroxylation of 3-hydroxybenzoic acid. The electron transfer compatibility and the coupling efficiency between the homologous FoCYP-FoCPR system are significant and it favored enhanced monooxygenase activity with broader substrate specificity.