日益增长的污染物给环境和人类带了严重的破坏，研究微生物对其降解及调控，对认识微生物如何适应污染物以及提高其生物修复的能力具有重要意义。假单胞菌WBC-3经对苯二酚代谢环境优先污染物4-硝基酚，其编码代谢的基因簇位于3个不同的操纵子上。本课题组前期研究表明除了LysR家族的PnpR外，该菌株中另一个LysR家族蛋白PnpM也可能参与该代谢途径的调控。因此本项目拟通过包括EMSA、DNaseI 足迹、甲醛交联及染色质免疫沉淀等研究手段，在体内和体外研究PnpM参与调控4-硝基酚的代谢机理，以及它与PnpR之间可能的相互作用，从而在分子生物学、生物化学和生理代谢等水平上完整地阐述WBC-3菌株中4-硝基酚经由对苯二酚代谢途径的转录调控机制，并揭示多元调控因子协同调控同一代谢操纵子的机理。这对于进一步阐明微生物分解代谢硝基酚污染物的调控机理及其适应性进化机制具有重要意义。

The ever-increasing pollutants have caused devastating damage to the natural environment and mankind. It is of significance to study the microbial degradation of environmental pollutants as well as the transcriptional regulation for such process, as it will certainly help us understand better how microbes adapt to the polluted-environment and also improve their bioremediation capacity. Pseudomonas strain WBC-3 metabolizes the environmental priority pollutant para-nitrophenol (PNP) via hydroquinone and the enzymes involved in the PNP catabolism are located on three different operons. Our previous study revealed that, in addition to the LysR-type PnpR, an extra transcriptional regulator was probably also involved in the PNP catabolism in this strain. Now we have demonstrated that, like PnpR, a pnpM-encoded LysR-type regulator was also necessary for the growth of this strain. By using approaches including EMSA, DNaseI foot printing and ChIP, this proposed project is to conduct a comprehensive and systematic research on the regulation of PNP degradation at biochemical and physiological levels, particularly aiming to identify the transcriptional regulators in the catabolism of PNP and the catabolic intermediate hydroquinone respectively, as well as their regulatory mechanisms and possible interaction between regulators PnpR and PnpM in vitro and in vivo. This will illustrate an example of the involvement of multiple regulators in controlling the same catabolic operon, and will also help reveal the molecular mechanisms underlying microbial adaptive evolution in the PNP catabolism.