NADPH oxidase activator P67phox behaves in solution as a multidomain protein with semi-flexible linkers
NADPH oxidase activator P67phox behaves in solution as a multidomain protein with semi-flexible linkers
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DOI：
10.1016/j.jsb.2009.08.009
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发表时间：
2010-01-01
影响因子：
3
通讯作者：
Fieschi, Franck
中科院分区：
文献类型：
--
作者：
Durand, Dominique;Vives, Corinne;Fieschi, Franck
NADPH氧化酶复合物通过产生活性氧参与吞噬病原体的破坏。这种可激活的复合物由膜异二聚体黄细胞色素B、小G蛋白Rac 1/Rac 2和胞质因子p47（phox）、p67（phox）和p40（phox）组成。p67（phox），由于其模块化结构，是NADPH氧化酶组分，尽管其在激活中的强制性作用及其在整个复杂组织中的中心位置，但其整体结构信息是最稀缺的。事实上，p67（phox）是与所有其他因子建立相互作用的唯一因子。在这项研究中，我们报告的SAXS分析p67（phox）。我们的数据表明，p67（phox）的行为作为一个多域蛋白质与半柔性连接。一方面，它似乎是一个非常细长的分子，其各种结构域组织成一串珠子。链接器被预测为部分或主要是非结构化的，我们的实验数据的功能确实指向域间的灵活性。另一方面，我们的工作还表明，蛋白质并不像非结构化接头所允许的那样延伸，从而暗示了p67（phox）内存在分子内相互作用。我们建议，在溶液中的p67（phox）构象的双重字符是中央，以确保众多的相互作用被容纳。(C)2009 Elsevier Inc. All rights reserved.
The NADPH oxidase complex is involved in the destruction of phagocytosed pathogens through the production of reactive oxygen species. This activatable complex consists of a membranous heterodimeric flavocytochrome b, a small G-protein Rac1/Rac2 and cytosolic factors, p47(phox), p67(phox) and p40(phox). p67(phox), due to its modular structure, is the NADPH oxidase component for which global structure information is most scarce despite its mandatory role in activation and its central position in the whole complex organization. Indeed, p67(phox) is the only factor establishing interaction with all others. In this study, we report the SAXS analysis of p67(phox). Our data reveals that p67(phox) behaves as a multidomain protein with semi-flexible linkers. On the one hand, it appears to be a very elongated molecule with its various domains organized as beads on a string. Linkers are predicted to be partially or mainly unstructured and features of our experimental data do point towards inter-domain flexibility. On the other hand, our work also suggests that the protein is not as extended as unstructured linkers could allow, thereby implying the existence of intra-molecular interactions within p67(phox). We suggest that the dual character of p67(phox) conformation in solution is central to ensure the numerous interactions to be accommodated. (C) 2009 Elsevier Inc. All rights reserved.