Cytochrome P450 BM3 (CYP102A1)

Cytochrome P450 BM3 is a soluble, bacterial cytochrome P450 enzyme originally identified in *Bacillus megaterium*. It is encoded by the CYP102A1 gene and is notable because it is a natural fusion of both the cytochrome P450 heme domain and an NADPH-dependent diflavin reductase domain within a single polypeptide chain. This self-sufficient monooxygenase catalyzes the hydroxylation of long-chain fatty acids (typically at ω–1 to ω–3 positions) and functions via electron transfer through the heme iron, enabling substrate oxidation by molecular oxygen. Cytochrome P450 BM3 is widely used as a model for structure-function studies in the P450 superfamily, directed evolution, and for protein engineering to create novel biocatalysts for industrial and pharmaceutical applications. Although it is not a direct human drug target, its engineered variants support studies of drug metabolism and synthetic chemistry.

Other names

Cytochrome P450 monooxygenase BM3CYP102A1Flavoprotein monooxygenaseAryl hydrocarbon hydroxylaseAryl-4-monooxygenaseXenobiotic monooxygenaseMicrosomal P450Microsomal monooxygenase

Monooxygenation via "H atom abstraction/•OH recombination"; Electron transfer from NADPH to heme via covalently fused FAD/FMN reductase domains; Formation of catalytic heme-Fe=O (Compound I) intermediate used for hydroxylation and sulfoxidation