bphX基因提高Cupriavidus basilensis中联苯双加氧酶催化效率的分子机制研究

bph操纵子编码的蛋白构成了多溴二苯醚等多种难降解污染物的降解代谢途径，而其中起到关键作用的是bphA1、bphA2、bphA3和bphA4等基因编码的联苯2,3-双加氧酶（BPDO）。在不同细菌的bph操纵子中，bphX基因和bphA1-A4等基因在空间位置上存在极其紧密的关联，然而对bphX的功能却一直无法解释。本项目以自主分离的高效多溴二苯醚降解菌Cupriavidus basilensis WS为研究对象，在前期已证实其bphX基因可强化BPDO催化效率的基础上，结合遗传学、分子生物学、生物信息学等手段，对BphX的性质及功能展开研究，证实BphX为细胞内膜蛋白，阐明BphX强化BPDO催化效率的分子机制，进一步完善对bph操纵子结构、功能的理解。本项目研究成果有望明确bphX基因在多溴二苯醚降解过程中扮演的角色及其在bph操纵子进化中的重要意义，有助于相关降解途径的改造和开发。

The proteins encoded by the bph operon constitute catabolic pathways for various refractory pollutants, such as polybrominated diphenyl ethers (PBDE). The biphenyl 2,3-dioxygenase (BPDO) encoded by bphA1, bphA2, bphA3, and bphA4 genes plays a key role in this catabolic pathway. Among the bph operons obtained from different bacteria, the bphX and bphA1–A4 genes are closely related in spatial position, however, the function of bphX has not yet been explained. We use a self-separated high-efficiency PBDE-degrading bacteria Cupriavidus basilensis WS in our study. Our previous studies confirmed that the bphX gene can enhance the catalytic efficiency of BPDO; therefore, we will study the properties and functions of bphX with a combination of methods involving genetics, molecular biology, and bioinformatics. We will confirm that bphX is an intracellular membrane protein. Next, the molecular mechanism of bphX involved in the improvement of the catalytic efficiency of BPDO will be elucidated. This will further improve the understanding of the structure and function of bph operons. Our results will explain the role of the bphX gene in the degradation process of PBDE and its significance in the evolution of bph operons. This would contribute to the modification and development of relevant degradation pathways in the future.