Development of a P450 Fusion Enzyme for Biaryl Coupling in Yeast

Cytochrome P450 Mediated Cyclohexane Ring Formation in Forazoline Biosynthesis

Forazoline A, produced by the marine actinomycete Actinomadura sp. WMMB-499, is a unique PK/NRP hybrid macrolactone with promising antifungal in vivo efficacy through a previously unreported mechanism. Although a PKS/NRPS gene cluster was identified as a candidate for forazoline production, the precise biosynthetic pathway and the functions of the tailoring enzymes remain unclear. In this work, the functions of three cytochrome P450 mono-oxygenases (FrazP1P2P3) were characterized. Notably, FrazP2 was found to mediate cyclohexane ring formation from an 1,3,6-triene precursor during forazoline A biosynthesis, as confirmed by genetic and biochemical analysis. To gain structural and mechanistic insight into the activity of FrazP2, the crystal structure of a FrazP2-substrate complex has been solved at 2.3 Å resolution. The molecular dynamics simulations and DFT calculations revealed an unprecedented enzyme-catalyzed oxidative cyclization reaction by FrazP2. These findings expand our understanding of the catalytic diversity of cytochrome P450s, contributing to the diversification of natural products and enabling the creation of unnatural derivatives with increased antifungal potency.

Efficient C25-Hydroxylation of Vitamin D3 Utilizing an Artificial Self-Sufficient Whole-Cell Cytochrome P450 Biocatalyst

Cytochrome P450 enzymes (P450s) are promising candidates for the biosynthesis of 25-hydroxyvitamin D3 (25(OH)VD3). However, their industrial application is limited by challenges, such as low stability, inefficient catalysis, and uncoupling reactions. The construction of self-sufficient P450s offers a strategic solution to these limitations, but requires linker optimization to regulate interdomain conformational dynamics. In this study, we integrated whole-cell biocatalyst screening with systematic optimization of reaction conditions, including cosolvents, cell concentrations, and plasmid selection, to enhance catalytic performance. Under optimized conditions, the heme domain Vdh-K1 achieved a 91.6% conversion efficiency and was subsequently selected for chimeric enzyme assembly. By employing local energetic frustration analysis to evaluate protein flexibility and allosteric dynamics, we identified chimeric P450 variants with highly frustrated linkers. The optimal variant, VK1-CYP116B46-L21, exhibited improved thermostability, catalytic activity, and coupling efficiency, achieving a yield of 4.89 mM (1.96 g/L) 25(OH)VD3 in Escherichia coli whole-cell catalysis─the highest reported yield to date. This work underscores the utility of computational frustration analysis in refining linker dynamics for multidomain enzymes and establishes a scalable, cost-effective framework to advance P450s systems for industrial biosynthesis of high-value compounds.

Recent advances in oxidative phenol coupling for the total synthesis of natural products

Covering: 2008 to 2023This review will describe oxidative phenol coupling as applied in the total synthesis of natural products. This review covers catalytic and electrochemical methods with a brief comparison to stoichiometric and enzymatic systems assessing their practicality, atom economy, and other measures. Natural products forged by C-C and C-O oxidative phenol couplings as well as from alkenyl phenol couplings will be addressed. Additionally, exploration into catalytic oxidative coupling of phenols and other related species (carbazoles, indoles, aryl ethers, etc.) will be surveyed. Future directions of this particular area of research will also be assessed.