组氨酸激酶BphS和应答因子BphT共同在转录水平调控多溴联苯醚（PBDE）降解基因，但其分子机制尚不清楚，直接限制了PBDE生物降解的应用。本项目以Bacillus sp.DB-17中的BphS/BphT为靶标，分别从蛋白和核酸角度研究PBDE诱导下BphS/BphT识别降解基因启动子的机制：1.通过大规模突变、高通量筛选及分子互作研究，明确BphS上接受PBDE诱导信号的结合位点，并分析BphT上负责启动子识别的关键氨基酸位点；2.通过转录组获取大量受BphS/BphT调控的启动子，分析其中保守核苷酸与BphT的互作，并采用Dnase I指纹等分析BphT直接接触的核苷酸位点；3.综合蛋白和启动子两方面的信息，初步得出双组份系统受PBDE诱导并选择性识别启动子的分子机制。本项目将解析PBDE降解基因转录调控元件的序列特征及其生物学意义，有助于最终阐明细菌对卤代芳香烃的信号识别过程。

Together, histidin kinase BphS and response regulator BphT regulate the polybrominated diphenyl ether (PBDE) degradation genes at transcription level. But the molecular mechanism of the regulation process was still unknown, which hindered the application of biodegradation of PBDE. Focusing on the two-component transduction system BphS/BphT of Bacillus sp. DB-17, this project will try to uncover the mechanism behind the PBDE induced selective recognition of promoters by BphS/BphT: 1.by combining large scale mutation, high throughput screening and study of molecular interactions, find the promoter recognition or interaction sites on BphT, meanwhile also find the positions on BphS that interact with PBDE and accept induction; 2.fetch other BphS/BphT regulated promoters using RNA-seq, analyzing the interactions between the conservative nucleotides on the promoters and BphT, meanwhile find the nucleotides which have direct interactions with BphT using Dnase I footprint; 3.combining the results from proteins and promoter, illustrate the molecular mechanism of induction of the two-component system by PBDE and the recognition of promoter by the two-component system. The research will uncover the sequence features of the regulation elements of PBDE degradation genes and explain their biological meaning, finally illustrate the bacterial signal transduction process for aryl halides.