Centre de Génétique Moléculaire, UPR 3404, CNRS, 1 Av. de Terrasse, 91198, Gif-sur-Yvette Cedex, France.
Biochem J. 2011 Apr 1;435(1):197-206. doi: 10.1042/BJ20101984.
CPR (NADPH-cytochrome P450 reductase) is a multidomain protein containing two flavin-containing domains joined by a connecting domain thought to control the necessary movements of the catalytic domains during electronic cycles. We present a detailed biochemical analysis of two chimaeric CPRs composed of the association of human or yeast FMN with the alternative connecting/FAD domains. Despite the assembly of domains having a relatively large evolutionary distance between them, our data support the idea that the integrity of the catalytic cycle is conserved in our chimaeric enzymes, whereas the recognition, interactions and positioning of both catalytic domains are probably modified. The main consequences of the chimaerogenesis are a decrease in the internal electron-transfer rate between both flavins correlated with changes in the geometry of chimaeric CPRs in solution. Results of the present study highlight the role of the linker and connecting domain in the recognition at the interfaces between the catalytic domains and the impact of interdomain interactions on the redox potentials of the flavins, the internal electron-transfer efficiency and the global conformation and dynamic equilibrium of the CPRs.
CPR（NADPH-细胞色素 P450 还原酶）是一种含有两个黄素结合域的多功能蛋白，通过一个连接域连接，该连接域被认为在电子循环过程中控制催化域的必要运动。我们对由人源或酵母 FMN 与替代连接/FAD 域组成的两种嵌合 CPR 进行了详细的生化分析。尽管组装的域之间具有相对较大的进化距离，但我们的数据支持这样一种观点，即催化循环的完整性在我们的嵌合酶中得到了保守，而两个催化域的识别、相互作用和定位可能发生了改变。嵌合发生的主要后果是两个黄素之间的内部电子转移率降低，这与嵌合 CPR 在溶液中的构象变化有关。本研究的结果强调了连接子和连接域在催化域之间的识别中的作用，以及域间相互作用对黄素的氧化还原电位、内部电子转移效率以及 CPR 的整体构象和动态平衡的影响。
