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还原为非芳香环二烯;该反应由2 ATP的水解驱动。ATP水解导致电子的能量化，并伴随着从S = 1/2到S = 7/2的还原酶的高自旋EPR信号的切换。同时，它诱导了两个[4Fe-4S]团簇的可逆磁相互作用。我们假设连续的单电子转移和质子化步骤中的脱芳构化过程（伯奇还原）。ATP水解将与电子活化偶联，电子活化是克服第一电子转移到芳环的高氧化还原势垒（E’o =-1.9V）所需的。我们在苯甲酰辅酶A还原酶的结构/功能关系中获得更深入见解的方法包括光谱学（EPR-，Mössbauer-，MCD-光谱学），晶体学/X射线分析和分子生物学技术（异源表达含有亚基的部分活性）以及底物结合研究。这是可能的调查ATP依赖的电子激活分开的电子转移到芳环。我们试图了解一个相对简单的氧化还原模块的酶如何将ATP水解的能量转化为脱芳构化过程所需的氧化还原能量。

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.