Structural insight into the electron transfer pathway of a self-sufficient P450 monooxygenase
Lilan Zhang, Zhenzhen Xie, Ziwei Liu, Shuyu Zhou, Lixin Ma, Weidong Liu, Jian‐Wen Huang, Tzu‐Ping Ko, Xiuqin Li, Yuechan Hu, Jian Min, Xuejing Yu, Rey‐Ting Guo, Chun‐Chi Chen
Abstract
Cytochrome P450 monooxygenases are versatile heme-thiolate enzymes that catalyze a wide range of reactions. Self-sufficient cytochrome P450 enzymes contain the redox partners in a single polypeptide chain. Here, we present the crystal structure of full-length CYP116B46, a self-sufficient P450. The continuous polypeptide chain comprises three functional domains, which align well with the direction of electrons traveling from FMN to the heme through the [2Fe-2S] cluster. FMN and the [2Fe-2S] cluster are positioned closely, which facilitates efficient electron shuttling. The edge-to-edge straight-line distance between the [2Fe-2S] cluster and heme is approx. 25.3 Å. The role of several residues located between the [2Fe-2S] cluster and heme in the catalytic reaction is probed in mutagenesis experiments. These findings not only provide insights into the intramolecular electron transfer of self-sufficient P450s, but are also of interest for biotechnological applications of self-sufficient P450s.