PDF(Pubmed)
Abstract：
Metal cofactors are essential for catalysis and enable countless conversions in nature. Interestingly, the metal cofactor is not always static but mobile with movements of more than 4 Å. These movements of the metal can have different functions. In the case of the xylose isomerase and medium-chain dehydrogenases, it clearly serves a catalytic purpose. The metal cofactor moves during substrate activation and even during the catalytic turnover. On the other hand, in class II aldolases, the enzymes display resting states and active states depending on the movement of the catalytic metal cofactor. This movement is caused by substrate docking, causing the metal cofactor to take the position essential for catalysis. As these metal movements are found in structurally and mechanistically unrelated enzymes, it has to be expected that this metal movement is more common than currently perceived. KEY POINTS: • Metal ions are essential cofactors that can move during catalysis. • In class II aldolases, the metal cofactors can reside in a resting state and an active state. • In MDR, the movement of the metal cofactor is essential for substrate docking.
摘要：
金属辅因子对于催化是必不可少的，并且能够在自然界中进行无数的转化。有趣的是,金属辅因子并不总是静态的，而是移动的，运动超过4µ。金属的这些运动可以具有不同的功能。在木糖异构酶和中链脱氢酶的情况下，它显然有催化作用。金属辅因子在底物活化期间甚至在催化转换期间移动。另一方面,在II类醛缩酶中，酶根据催化金属辅因子的运动显示静止状态和活性状态。这种运动是由基板对接引起的，使金属辅因子占据催化必不可少的位置。由于这些金属运动是在结构和机械无关的酶中发现的，必须预期这种金属运动比目前认为的更普遍。关键点:•金属离子是在催化过程中可以移动的重要辅因子。•在II类醛缩酶中，金属辅因子可以处于静止状态和活性状态。•在MDR中，金属辅因子的移动对于基板对接是必不可少的。
