微生物降解是目前公认的环境中多环芳烃清除的主要途径，对高分子量多环芳烃降解途径、降解机制的研究是国内外研究的热点。申请者前期分离到一株具强降解多环芳烃能力的海洋红球菌P14，通过对其降解途径及基因组信息的研究，首次发现一种来源于细菌的能催化四环以上的多环芳烃环氧化、且底物范围较广的细胞色素P450单加氧酶-CYP108J1，且该基因的表达可能受其上游存在的两个LuxR家族调控蛋白NarL和MatL的调控。本项目拟利用生物信息学、生化与分子生物学等技术，研究CYP108J1底物范围、底物结合位点、催化反应机制、酶结构与功能的关系，探索调控蛋白NarL、MatL等对CYP108J1基因表达的调控机制。本研究项目将为有助于揭示红球菌P14降解多环芳烃的分子机制，为P450单加氧酶应用于环境中芳香性污染物的降解中提供理论基础。

At present, microbial degradation is usually considered as the main pathway of removing the polycyclicaromatic hydrocarbons (PAHs) in the environment, and the study on their pathway and molecular mechanism on high-molecular-weight (HMW) PAHs biodegradation is one of the hot scientific topics in the current world. In our previous study, one marine bacterial strain Rhodococcus sp. P14 was isolated with a strong ability of PAHs degradation. Via the analysis of its biodegradation pathway as well as the whole genome, we firstly demonstrated that strain P14 has a cytochrome P450 monooxygenase CYP108J1, which can catalyze the epoxidation process of four different PAHs, including benz[a]anthracene. In CYP108J1 gene cluster, there are two LuxR family regulatory proteins (NarL and MatL), which might regulate the expression of gene cyp108J1. Through the use of bioinformatics, biochemistry and molecular biology techniques, this proposal intends to investigate the substrate range of CYP108J1, the substrate binding site, the catalytic reaction mechanism as well as the enzyme structure-function relationship for further exploring the regulative mechanism of regulatory proteins (NarL and MatL) involved in gene expression of CYP108J1.The results will help to reveal the molecular mechanism of strain P14 on the degradation of PAHs compounds and also accelerate the application of utilizing P450 monooxygenase of PAHs pollution control.