Department of Microbiology, College of Life Sciences, Nankai University, Tianjin, 300071, China.
Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, Tianjin, 300071, China.
Appl Microbiol Biotechnol. 2022 Sep;106(17):5687-5699. doi: 10.1007/s00253-022-12090-y. Epub 2022 Jul 30.
Antibiotic resistance genes are usually tightly controlled by transcription factors and RNA regulatory elements including sRNAs, riboswitches, and attenuators, and their expression is activated to respond to antibiotic exposure. In previous work, we revealed that the rppA gene is regulated by attenuator LRR and two mistranslation products in Bacillus thuringiensis BMB171. However, its function and promoter regulation is still not precise. In this study, we demonstrated that the encoding product of the rppA gene acts as an ARE1 ABC-F protein and confers resistance to antibiotics virginiamycin M1 and lincomycin when overexpressed. Besides the reported attenuator LRR, the expression of the rppA gene is controlled by the sigma factor SigA and a global transcription factor CcpA. Consequently, its promoter activity is mainly maintained at the stationary phase of cell growth and inhibited in the presence of glucose. Our study revealed the function and regulation of the rppA gene in detail. KEY POINTS: • The RppA protein acts as an ARE1 ABC-F protein • The rppA gene confers resistance to antibiotics virginiamycin M1 and lincomycin when overexpressed • The expression of the rppA gene is regulated by the sigma factor SigA and the pleiotropic regulator CcpA.
抗生素耐药基因通常受到转录因子和 RNA 调节元件的紧密控制，包括 sRNAs、核糖体开关和衰减子，它们的表达被激活以响应抗生素暴露。在以前的工作中，我们揭示了 rppA 基因在苏云金芽孢杆菌 BMB171 中受到衰减子 LRR 和两种翻译错误产物的调节。然而，其功能和启动子调节仍然不精确。在这项研究中，我们证明了 rppA 基因的编码产物作为 ARE1 ABC-F 蛋白发挥作用，并在过表达时赋予抗生素维吉霉素 M1 和林可霉素的抗性。除了报道的衰减子 LRR 外，rppA 基因的表达还受到 sigma 因子 SigA 和全局转录因子 CcpA 的控制。因此，其启动子活性主要在细胞生长的静止期维持，并在存在葡萄糖时受到抑制。我们的研究详细揭示了 rppA 基因的功能和调节。要点：•RppA 蛋白作为 ARE1 ABC-F 蛋白发挥作用•过表达 rppA 基因可赋予抗生素维吉霉素 M1 和林可霉素的抗性•rppA 基因的表达受 sigma 因子 SigA 和多功能调节因子 CcpA 的调节。
