State Key Laboratory of Agricultural Microbiology, College of Life Science and Technology, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.
Appl Microbiol Biotechnol. 2019 Mar;103(6):2701-2713. doi: 10.1007/s00253-019-09666-6. Epub 2019 Feb 7.
Alishewanella sp. WH16-1 is a heavy metal-resistant bacterium. Previously, a putative YebC family regulator gene, designated ruvR, was associated with Cr(VI) resistance. In this study, comprehensive analyses were performed to study the role of ruvR and its adjunct putative DNA repairing genes, ruvCAB, in the heavy metal resistance of Alishewanella sp. WH16-1. RT-PCR analysis showed that ruvR is cotranscribed with ruvCAB. Gene mutation and complementation experiments indicated that ruvRCAB contributes to Cr(VI), As(III), Sb(III), and Cd(II) resistance in vivo. Random amplification of polymorphic DNA-PCR revealed that ruvCAB is associated with DNA repair mediated by these metals, and the presence of the metals in the cells was confirmed by elemental mapping and energy-dispersive X-ray spectrograph analysis. In addition, qRT-PCR, reporter gene assay, and in vivo and in vitro protein-DNA interaction experiments indicated that RuvR positively regulates the transcription of ruvCAB and is induced by Cr(VI). Finally, site-directed mutagenesis demonstrated that Asp103 is essential for the DNA binding ability of RuvR. The above results suggest that RuvR is involved in Cr(VI) resistance and resistance to other metals and that RuvR positively regulates the expression of ruvCAB. Based on our study and literatures, a model of RuvRCAB detailing bacterial heavy metal resistance is proposed. The RuvRCAB system plays an important role in the ability of Alishewanella sp. WH16-1 to survive in environments with heavy metals.
希瓦氏菌属 WH16-1 是一种重金属抗性细菌。先前，一个假定的 YebC 家族调节基因，命名为 ruvR，与 Cr(VI)抗性有关。在本研究中，对 ruvR 及其附属假定的 DNA 修复基因 ruvCAB 在希瓦氏菌属 WH16-1 重金属抗性中的作用进行了综合分析。RT-PCR 分析表明，ruvR 与 ruvCAB 共转录。基因突变和互补实验表明，ruvRCAB 有助于希瓦氏菌属 WH16-1 体内 Cr(VI)、As(III)、Sb(III)和 Cd(II)的抗性。随机扩增多态性 DNA-PCR 显示，ruvCAB 与这些金属介导的 DNA 修复有关，并且通过元素映射和能量色散 X 射线光谱分析证实了细胞中存在这些金属。此外，qRT-PCR、报告基因分析、体内和体外蛋白-DNA 相互作用实验表明，RuvR 正向调节 ruvCAB 的转录，并受 Cr(VI)诱导。最后，定点突变实验表明 Asp103 对 RuvR 的 DNA 结合能力至关重要。上述结果表明，RuvR 参与 Cr(VI)抗性和其他金属抗性，并且 RuvR 正向调节 ruvCAB 的表达。基于我们的研究和文献，提出了一个详细描述细菌重金属抗性的 RuvRCAB 模型。RuvRCAB 系统在希瓦氏菌属 WH16-1 适应重金属环境的能力中发挥着重要作用。
