Crystal Structure of Cytochrome P450 (CYP105P2) from Streptomyces peucetius and Its Conformational Changes in Response to Substrate Binding

Cytochrome P450 monooxygenases (CYP, EC 1.14.14.1) belong to a large family of enzymes that catalyze the hydroxylation of various substrates. Here, we present the crystal structure of CYP105P2 isolated from Streptomyces peucetius ATCC27952 at a 2.1 Å resolution. The structure shows the presence of a pseudo-ligand molecule in the active site, which was co-purified fortuitously and is presumed to be a biphenyl derivative. Comparison with previously determined substrate-bound CYP structures showed that binding of the ligand produces large and distinctive conformational changes in α2–α3, α7–α9, and the C-terminal loop regions. This structural flexibility confirms our previous observation that CYP105P2 can accommodate a broad range of ligands. The structure complexed with a pseudo-ligand provides the first molecular view of CYP105P2–ligand interactions, and it indicates the involvement of hydrophobic residues (Pro82, Ala181, Met187, Leu189, Leu193, and Ile236) in the interactions between hydrophobic ligands and CYP105P2. These results provide useful insights into the structural changes involved in the recognition of different ligands by CYP105P2.