ATP-getriebener Elektronentransport der Benzoyl-CoA Reduktase

铁硫酶苯甲酰辅酶A还原酶催化苯甲酰辅酶A还原为非芳香族环二烯，该反应是由2三磷酸腺苷的水解酶驱动的。三磷酸腺苷的水解导致一个电子的能化，并伴随着从S=1/2到S=7/2的转换。平行地诱导了两个[4Fe-4S]团簇的可逆磁相互作用。我们假设在脱芳构化过程(Birch还原)中连续的单电子转移和质子化步骤。为了克服第一个电子转移到芳环的高氧化还原势垒(E‘O=-1.9V)，ATP的水解会与电子活化相耦合。我们深入了解苯甲酰辅酶A还原酶结构/功能关系的方法包括光谱学(EPR-、Mössbauer-、MCD-光谱)、结晶学/X射线分析和分子生物学技术(含有亚基的部分活性的异源表达)以及底物结合研究。可以从芳香环的电子转移出发，单独研究依赖于ATP的电子活化。我们试图理解一个具有相对简单的氧化还原模块的酶是如何将ATP水解的能量转化为脱芳构化过程所需的氧化还原能量的。

The iron-sulfur-enzyme benzoyl-CoA reductase catalyzes the reduction of benzoyl-CoA to a non-aromatic cyclic diene; this reaction is driven by the hydrolysis of 2 ATP. ATP hydrolysis results in the energetization of an electron and is accompanied by a switch from S = 1/2 to S = 7/2 high-spin EPR signals of the reduced enzyme. In parallel it induces the reversible magnetic interaction of two [4Fe-4S] clusters. We postulate consecutive one-electron transfer and protonation steps in the dearomatization process (Birch reduction). ATP hydrolysis would be coupled to electron activation which is required to overcome the high redox barrier (E'o = -1.9 V) for the first electron transfer to the aromatic ring. Our approaches in getting deeper insights in the structure/function relationships of benzoyl-CoA reductase include spectroscopical (EPR-, Mössbauer-, MCD-spectroscopy), crystallographical/X-ray analytical and molecular biological techniques (heterologous expression of part-activities containing subunits) as well as substrate binding studies. It is possible to investigate the ATP-dependent electron activation separately from the electron transfer to the aromatic ring. We attempt to understand how an enzyme with relatively simple redox modules transfers the energy of ATP hydrolysis into the redox energy required for the dearomatization process.