Wang Ze-Jun, Chen Fu, Xu Ya-Qian, Huang Peng, Liu Shu-Shen
Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
Biology (Basel). 2021 Jul 9;10(7):638. doi: 10.3390/biology10070638.
Bioluminescent bacteria are mainly found in marine habitats. sp.-Q67 (Q67), a nonpathogenic freshwater bacterium, has been a focus due to its wide use in the monitoring of environmental pollution and the assessment of toxicity. However, the lack of available crystal structures limits the elucidation of the structures of the functional proteins of the quorum-sensing (QS) system that regulates bacterial luminescence in Q67. In this study, 19 functional proteins were built through monomer and oligomer modeling based on their coding proteins in the QS system of Q67 using MODELLER. Except for the failure to construct LuxM due to the lack of a suitable template, 18 functional proteins were successfully constructed. Furthermore, the relationships between the function and predicted structures of 19 functional proteins were explored one by one according to the three functional classifications: autoinducer synthases and receptors, signal transmission proteins (phosphotransferases, an RNA chaperone, and a transcriptional regulator), and enzymes involved in bacterial bioluminescence reactions. This is the first analysis of the whole process of bioluminescence regulation from the perspective of nonpathogenic freshwater bacteria at the molecular level. It provides a theoretical basis for the explanation of applications of Q67 in which luminescent inhibition is used as the endpoint.
生物发光细菌主要存在于海洋栖息地。sp.-Q67（Q67）是一种非致病性淡水细菌，因其在环境污染监测和毒性评估中的广泛应用而备受关注。然而，缺乏可用的晶体结构限制了对Q67中调节细菌发光的群体感应（QS）系统功能蛋白结构的阐明。在本研究中，利用MODELLER根据Q67的QS系统中的编码蛋白，通过单体和寡聚体建模构建了19种功能蛋白。除了由于缺乏合适的模板而未能构建LuxM外，成功构建了18种功能蛋白。此外，根据自动诱导物合成酶和受体、信号转导蛋白（磷酸转移酶、一种RNA伴侣和一种转录调节因子）以及参与细菌生物发光反应的酶这三种功能分类，逐一探索了19种功能蛋白的功能与预测结构之间的关系。这是首次从非致病性淡水细菌的分子水平角度对生物发光调节的全过程进行分析。它为解释以发光抑制为终点的Q67的应用提供了理论依据。
