Substrate binding induces structural changes in cytochrome P450cam.
The binding of (+)-camphor to cytochrome P450cam (P450cam) expels a cluster of waters at the active site, raising the redox potential of the haem to an extent that allows reduction by the electron-transfer system. This binding was reported to involve no significant structural changes in the protein. Here, two ferric P450cam structures partially complexed with (+)-camphor were determined by X-ray crystallography at 1.30-1.35 A resolution, revealing the structures of the substrate-free and substrate-bound forms. (+)-Camphor binding induces rotation of Thr101 to form a hydrogen bond that acts as a hydrogen donor to a peripheral haem propionate. This bonding contributes to the redox-potential change.
Sakurai
Keisuke
K
Institute for Protein Research, Osaka University, Suita 565-0871, Japan.
Shimada
Hideo
H
Hayashi
Takashi
T
Tsukihara
Tomitake
T
D001665:Binding Sites / Q000502:physiology; D019475:Camphor 5-Monooxygenase / Q000737:chemistry* / Q000378:metabolism*; D018360:Crystallography, X-Ray; D013379:Substrate Specificity / Q000502:physiology
D019475:Camphor 5-Monooxygenase