Crystal structure studies on sulfur oxygenase reductase from Acidianus tengchongensis
Crystal structure studies on sulfur oxygenase reductase from Acidianus tengchongensis
复制标题
腾冲酸杆菌硫加氧酶还原酶晶体结构研究
DOI：
10.1016/j.bbrc.2008.02.131
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发表时间：
2008-05-09
影响因子：
3.1
通讯作者：
Chang, Wenrui
中科院分区：
文献类型：
--
作者：
Li, Mei;Chen, Zhiwei;Chang, Wenrui
硫氧合酶还原酶(SOR)在分子氧存在下同时催化单质硫的氧化和还原生成亚硫酸盐、硫代硫酸盐和硫化物。本研究测定了腾冲酸奶SOR野生型和突变型(SOR-AT)两种不同晶型的晶体结构，观察到24个相同的SOR单体形成一个中空球体。在二十碳四聚体中，四聚体通道和三聚体通道分别被认为是底物和产物的通道。此外，SOR-AT结构与SCR-AA结构的比较表明，活性部位存在显著差异。首先，在SOR-AT结构中，Cys31没有被过硫化。其次，铁原子是五配位的，而不是六配位的，因为在SOR-AA结构中连接到铁原子的水分子中的一个丢失了。因此，提出了底物的结合位置和SOR的一个假想的催化过程。(C)2008 Elsevier Inc.保留所有权利。
Sulfur oxygenase reductase (SOR) simultaneously catalyzes oxidation and reduction of elemental sulfur to produce sulfite, thiosulfate, and sulfide in the presence of molecular oxygen. In this study, crystal structures of wild type and mutants of SOR from Acidianus tengchongensis (SOR-AT) in two different crystal forms were determined and it was observed that 24 identical SOR monomers form a hollow sphere. Within the icosatetramer sphere, the tetramer and trimer channels were proposed as the paths for the substrate and products, respectively. Moreover, a comparison of SOR-AT with SCR-AA (SOR from Acidianus ambivalens) structures showed that significant differences existed at the active site. Firstly, Cys31 is not persulfurated in SOR-AT structures. Secondly, the iron atom is five-coordinated rather than six-coordinated., since one of the water molecules ligated to the iron atom in the SOR-AA structure is lost. Consequently, the binding sites of substrates and a hypothetical catalytic process of SOR were proposed. (c) 2008 Elsevier Inc. All rights reserved.