F is R activates σ 54 ‐dependent transcription of sulfide‐oxidizing genes in C upriavidus pinatubonensis JMP 134

作者：Huanjie Li, Juan Li, Chuanjuan Lü, Yongzhen Xia, Yufeng Xin, Honglei Liu, Honglei Liu, Luying Xun, Huaiwei Liu, Huaiwei Liu · 发表于：Molecular Microbiology · 年份：2017 · DOI：10.1111/mmi.13725 · 被引用次数：60 · 研究领域：Chromium effects and bioremediation、Sulfur Compounds in Biology、Microbial Community Ecology and Physiology

Summary Some heterotrophic bacteria are able to oxidize sulfide (H 2 S, HS − and S 2− ) to sulfite and thiosulfate via polysulfide. The genes coding for the oxidation enzymes in Cupriavidus pinatubonensis JMP134 have recently been identified; however, their regulation is unknown. A regulator gene is adjacent to the operon of the sulfide‐oxidizing genes, encoding a σ 54 ‐dependent transcription factor (FisR) with three domains: an R domain, an AAA+ domain and a DNA‐binding domain. Here it is reported that the regulator responds to the presence of sulfide and activates the sulfide‐oxidizing genes. FisR binds to its cognate operator at −114 to −135 bp of the transcription start of the operon. When polysulfide reacts with the R domain of FisR through the three conserved cysteine residues (C53, C64 and C71), FisR activates the expression of the operon. FisR is highly sensitive to polysulfide, activating σ 54 ‐dependent transcription of sulfide‐oxidizing genes for sulfide removal. Further, sequence analysis indicates that FisR‐type regulators are relatively common for controlling sulfide‐oxidizing genes under sulfide stress in the Proteobacteria.