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bioRxiv · 10.1101/2024.12.22.630014

Non-Canonical Cytochrome P450 Enzymes in Nature

Nguy, A. K. L.·Ireland, K. A.·Kayrouz, C. M.·Caceres, J. C.·Greene, B. L.·Davis, K. M.·Seyedsayamdost, M. R.
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Abstract

Cytochrome P450s (CYPs) are a superfamily of thiolate-ligated heme metalloenzymes principally responsible for the hydroxylation of unactivated C-H bonds. The lower-axial cysteine is an obligatory and universally conserved residue for the CYP enzyme class. Herein, we challenge this paradigm by systematically identifying non-canonical CYPs (ncCYPs) that do not harbor a cysteine ligand. Our bioinformatic search reveals 20 distinct ncCYP families with diverse ligands encoded in microbial genomes. We characterize a native serine-ligated CYP with a high-spin ferric resting state. Its crystal structure clearly shows a typical CYP fold and a serine alkoxide as a lower axial heme ligand. In addition, we report the discovery and characterization of the first native selenocysteine-ligated CYP in nature. Our findings radically expand the CYP metalloenzyme family.

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Nguy, A. K. L., Ireland, K. A., Kayrouz, C. M., Caceres, J. C., Greene, B. L., Davis, K. M., Seyedsayamdost, M. R.. 2024-12-23. Non-Canonical Cytochrome P450 Enzymes in Nature. https://doi.org/10.1101/2024.12.22.630014

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