Choi H, Kim S, Mukhopadhyay P, Cho S, Woo J, Storz G, Ryu S E
Center for Cellular Switch Protein Structure, Korea Research Institute of Bioscience and, Biotechnology, P.O. Box 115, Yusong, 305-600, Taejon, South Korea
Cell. 2001 Apr 6;105(1):103-13. doi: 10.1016/s0092-8674(01)00300-2.
The Escherichia coli OxyR transcription factor senses H2O2 and is activated through the formation of an intramolecular disulfide bond. Here we present the crystal structures of the regulatory domain of OxyR in its reduced and oxidized forms, determined at 2.7 A and 2.3 A resolutions, respectively. In the reduced form, the two redox-active cysteines are separated by approximately 17 A. Disulfide bond formation in the oxidized form results in a significant structural change in the regulatory domain. The structural remodeling, which leads to different oligomeric associations, accounts for the redox-dependent switch in OxyR and provides a novel example of protein regulation by "fold editing" through a reversible disulfide bond formation within a folded domain.
大肠杆菌的OxyR转录因子可感知过氧化氢，并通过分子内二硫键的形成而被激活。在此，我们展示了还原态和氧化态OxyR调节结构域的晶体结构，分辨率分别为2.7 Å和2.3 Å。在还原态下，两个氧化还原活性半胱氨酸相距约17 Å。氧化态下二硫键的形成导致调节结构域发生显著的结构变化。这种结构重塑导致不同的寡聚体缔合，解释了OxyR中氧化还原依赖性开关，并提供了一个通过折叠结构域内可逆二硫键形成进行“折叠编辑”来调节蛋白质的新例子。
