Fuangthong Mayuree, Helmann John D
Department of Microbiology, Cornell University, Ithaca, NY 14853-8101,USA.
Proc Natl Acad Sci U S A. 2002 May 14;99(10):6690-5. doi: 10.1073/pnas.102483199. Epub 2002 Apr 30.
Reactive oxygen species induce the expression of detoxification and repair genes critical for life in an aerobic environment. Bacterial factors that sense reactive oxygen species use either thiol-disulfide exchange reactions (OxyR, RsrA) or redox labile 2Fe-2S clusters (SoxR). We demonstrate that the reduced form of Bacillus subtilis OhrR binds cooperatively to two adjacent inverted repeat sequences in the ohrA control region and thereby represses transcription. In the presence of organic hydroperoxides, OhrR is inactivated by the reversible oxidation of a single conserved cysteine residue to the corresponding cysteine-sulfenic acid, and perhaps to higher oxidation states.
活性氧诱导了在有氧环境中对生命至关重要的解毒和修复基因的表达。感知活性氧的细菌因子利用硫醇-二硫键交换反应（OxyR、RsrA）或氧化还原不稳定的2Fe-2S簇（SoxR）。我们证明，枯草芽孢杆菌OhrR的还原形式协同结合到ohrA控制区域中的两个相邻反向重复序列上，从而抑制转录。在有机氢过氧化物存在的情况下，OhrR通过单个保守半胱氨酸残基可逆氧化为相应的半胱氨酸亚磺酸，也许还会氧化为更高的氧化态而失活。
