Characterisation of CYP102A25 from B. marmarensis and CYP102A26 from P. halophilus: P450 homologues of BM3 with preference towards hydroxylation of medium chain fatty acids

Cytochrome P450 monooxgenases are highly desired biocatalysts due to their ability to catalyse a wide variety of chemically challenging C-H activation reactions. The CYP102A subfamily of enzymes are natural catalytically self-sufficient proteins consisting of a haem and FMN-FAD reductase domain fused in a single component system. They catalyse the oxygenation of saturated and unsaturated fatty acids to produce primarily ω-1, ω-2 and ω-3 hydroxy acids. These monooxygenases have broad applications in biotechnology however, their substrate range is still limited and there is a continued need to add diversity to this class of biocatalysts. Herein we present the characterization of two new members of this class of enzymes: CYP102A25 (BMar) from B. marmarensis and CYP102A26 (PHal) from P. halophilus, both of which express readily in a recombinant bacterial host. BMar exhibits the highest activity toward myristic acid and shows moderate activity towards unsaturated fatty acids. PHal exhibits broader activity towards mid chain saturated (C14-18) and unsaturated fatty acids. Furthermore, PHal shows good regioselectivity for hydroxylation of myristic acid targeting the ω-2 position for C-H activation.