Multidimensional Engineering Delivers a High-Performance C11α-Steroid Hydroxylase for Practical Application

The C11α-hydroxyl group is essential for many steroid drugs, yet chemical synthesis suffers from complex routes and environmental issues. Here, we isolate CYP68N3_ma, a fungal cytochrome P450 from Metarhizium anisopliae EEG016, which converts 17α-hydroxyprogesterone to 11α,17α-dihydroxyprogesterone. Expressing CYP68N3_ma in Saccharomyces cerevisiae enabled the highly specific bioconversion with a concentration of 0.16 mM. Structure-guided iterative saturation mutagenesis yielded the triple mutant N3M3 (F111A/E374H/T115I), increasing the concentration 13.8-fold to 2.21 mM. Molecular dynamics and near-attack conformation analysis revealed cooperative modulation of steric hindrance and hydrogen bonding that fine-tunes substrate orientation and enhances the near-attack conformation (NAC) formation. Expression in Komagataella phaffii improved conversion 3.8-fold over that in S. cerevisiae. Overexpression of heme synthesis enzyme HEM1, cytochrome b5, an ABC transporter, and knockout of HMX1 resulted in 10.6 g/L in flask and 24.8 g/L in high-cell density bioreactor. This study establishes a versatile, sustainable, and scalable biocatalytic route for steroid functionalization.