OxyR senses sulfane sulfur and activates the genes for its removal in Escherichia coli
Ningke Hou,
Zhenzhen Yan,
Kaili Fan,
Huanjie Li,
Rui Zhao,
Yongzhen Xia,
Luying Xun,
Huaiwei Liu
Affiliations
Ningke Hou
State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
Zhenzhen Yan
State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
Kaili Fan
State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
Huanjie Li
State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
Rui Zhao
State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
Yongzhen Xia
State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China
Luying Xun
State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China; School of Molecular Biosciences, Washington State University, Pullman, WA, 99164-7520, USA; Corresponding author. School of Molecular Biosciences, Washington State University, Pullman, WA, 99164-7520, USA
Huaiwei Liu
State Key Laboratory of Microbial Technology, Shandong University, Qingdao, 266237, People's Republic of China; Corresponding author. State Key Laboratory of Microbiology Technology, Shandong University, Qingdao, 266237, People's Republic of China.
Sulfane sulfur species including hydrogen polysulfide and organic persulfide are newly recognized normal cellular components, and they participate in signaling and protect cells from oxidative stress. Their production has been extensively studied, but their removal is less characterized. Herein, we showed that sulfane sulfur at high levels was toxic to Escherichia coli under both anaerobic and aerobic conditions. OxyR, a well-known regulator against H2O2, also sensed sulfane sulfur, as revealed via mutational analysis, constructed gene circuits, and in vitro gene expression. Hydrogen polysulfide modified OxyR at Cys199 to form a persulfide OxyR C199-SSH, and the modified OxyR activated the expression of thioredoxin 2 and glutaredoxin 1. The two enzymes are known to reduce sulfane sulfur to hydrogen sulfide. Bioinformatics analysis indicated that OxyR homologs are widely present in bacteria, including obligate anaerobic bacteria. Thus, the OxyR sensing of sulfane sulfur may represent a preserved mechanism for bacteria to deal with sulfane sulfur stress. Keywords: OxyR, Sulfane sulfur, Escherichia coli, Thioredoxin, Glutaredoxin
