Pearson P H, Bridger W A
J Biol Chem. 1975 Nov 10;250(21):8524-9.
The isolated alpha subunit or succinyl-CoA synthetase from Escherichia coli is capable of catalyzing one step of the overall reaction, namely its own phosphorylation by the substrate ATP. The data presented herein also suggest that the binding sites for other substrates (succinate, succinyl-CoA) are located either on the beta subunit or comprise part of both subunit types. From these observations and from our earlier finding that the two subunits species are necessary for the overall reaction, we propose that the active site is assembled at or close to the point of contact of the two subunits in the native alpha2beta2 enzymic structure.
从大肠杆菌中分离出的α亚基或琥珀酰辅酶A合成酶能够催化整个反应中的一步，即被底物ATP自身磷酸化。本文提供的数据还表明，其他底物（琥珀酸、琥珀酰辅酶A）的结合位点要么位于β亚基上，要么包含两种亚基类型的一部分。基于这些观察结果以及我们之前发现的两种亚基对于整个反应都是必需的这一发现，我们提出活性位点是在天然α2β2酶结构中两个亚基的接触点处或其附近组装而成的。
