嗜麦芽菌素P28合成调控机理的研究

Bacteriocins, extracellular proteinaceous bactericidal substances that are produced by many species of bacteria, are promising alternatives to antibiotics for treating bacterial infections because of their narrow bactericidal spectrum, high biosafety, and difficult to produce drug resistance. The synthesis of bacteriocin is controlled by the regulatory system of its own or host bacteria. In the previous work, a novel bacteriocin, maltocin P28, was isolated from an environment S. maltophilia strain and had exclusively and obviously bactericidal activity against multiple clinical S. maltophilia strains. In the following study, we found that the regulatory mechanism of maltocin P28 biosynthesis was distinct from the well studied colicins and pyocins. In this project, the following approaches, construction of chromosome mutation library, RNA-seq, gene knock-out, EMSA and DNase I footprinting, will be conducted to shed light on the regulatory mechanism of maltocin P28 production.

细菌素是一类由细菌合成并分泌的具有杀菌活力的蛋白复合物，具有杀菌谱窄、生物安全性高、不易产生耐药性等特性，因此是一种优良的抗生素替代物。细菌素的合成受自身或宿主菌的调控系统控制。在前期工作中，我们从一株来源于土壤的嗜麦芽寡养单胞菌中分离到一个新型的细菌素—嗜麦芽菌素P28，其对多株分离自临床的嗜麦芽寡养单胞菌具有专一高效的杀菌活性。后期研究发现，该细菌素合成的调控方式明显不同于已被深入研究的大肠杆菌素和脓菌素。本项目拟运用转座子突变文库构建、RNA-seq、基因敲除、凝胶阻滞、DNase I 足迹等分子生物学技术结合生物信息学手段揭示调控嗜麦芽菌素P28合成的分子机制。

在前期工作中，我们从一株来源于土壤的嗜麦芽寡养单胞菌中分离到一个新型的细菌素—嗜麦芽菌素P28，其对多株分离自临床的嗜麦芽寡养单胞菌具有专一高效的杀菌活性。有趣的是该细菌素合成的调控方式明显不同于已被深入研究的大肠杆菌素和脓菌素。.本项目运用基因敲除、凝胶阻滞等分子生物学技术结合生物信息学手段较全面地揭示了调控嗜麦芽菌素P28合成的分子机制。我们鉴定了3个参与细菌素合成的调控基因，其中ORF3和ORF6促进主要结构蛋白编码基因orf17转录， ORF5抑制orf17转录；而且调控蛋白之间存在相互调控的现象，ORF5抑制orf3转录，ORF3促进orf6转录。.本项目揭示的嗜麦芽菌素P28合成调控的新型分子机制，不仅丰富了学术界对细菌素合成调控的认识，也可以为日后嗜麦芽菌素抗菌制剂临床开发时的大批量生产提供指导。