Institute of Organic Chemistry, University of Würzburg, Am Hubland, 97074, Würzburg, Germany.
Department of Biochemistry, Theodor Boveri-Institute, University of Würzburg, Am Hubland, 97074, Würzburg, Germany.
Sci Rep. 2018 Jul 11;8(1):10490. doi: 10.1038/s41598-018-28802-2.
Despite their popularity as enzyme engineering targets structural information about Sucrose Phosphorylases remains scarce. We recently clarified that the Q345F variant of Bifidobacterium adolescentis Sucrose Phosphorylase is able to accept large polyphenolic substrates like resveratrol via a domain shift. Here we present a crystal structure of this variant in a conformation suitable for the accommodation of the donor substrate sucrose in excellent agreement with the wild type structure. Remarkably, this conformation does not feature the previously observed domain shift which is therefore reversible and part of a dynamic process rather than a static phenomenon. This crystallographic snapshot completes our understanding of the catalytic cycle of this useful variant and will allow for a more rational design of further generations of Sucrose Phosphorylase variants.
尽管蔗糖磷酸化酶作为酶工程的靶点很受欢迎，但关于它的结构信息仍然很少。我们最近澄清了双歧杆菌蔗糖磷酸化酶的 Q345F 变体能够通过结构域转移接受大的多酚类底物，如白藜芦醇。在这里，我们展示了该变体在一种构象中的晶体结构，这种构象适合容纳供体底物蔗糖，与野生型结构非常吻合。值得注意的是，这种构象不具有先前观察到的结构域转移，因此是可逆的，是一个动态过程的一部分，而不是静态现象。这个晶体快照完成了我们对这个有用变体的催化循环的理解，并将允许进一步设计蔗糖磷酸化酶变体的更合理的设计。
