蓝细菌PCC6803染色体上的毒素蛋白Slr0664与抗毒素蛋白Ssr1114的相互作用

Interaction between chromosome-encoded toxin Slr0664 and antitoxin Slr1114 of Cyanobacteria Synechocystis sp.PCC6803

摘要:

摘要:【目的】证明蓝细菌PCC6803染色体上的毒素－抗毒素系统（TA, toxin-antitoxin system）ssr1114/slr0664中毒素蛋白Slr0664与抗毒素蛋白Ssr1114之的相互作用。【方法】构建在大肠杆菌（Escherichia coli）BL21（DE3）中诱导表达H6-Ssr1114或共表达H6-Ssr1114和Slr0664的重组质粒，诱导表达后借助亲和捕捉技术在不同的条件下纯化H6-Ssr1114或共纯化重组蛋白H6-Ssr1114和Slr0664，并通过肽谱分析共纯化的重组蛋白,证明H6-Ssr1114与Slr0664之间存在相互作用。【结果】诱导Slr0664表达对细胞产生毒性作用导致生长抑制或细胞死亡，诱导H6-Ssr1114和Slr0664共表达时细胞能能正常生长，在非变性条件下可纯化共表达的重组蛋白H6-Ssr1114和Slr0664，在变性条件下仅H6-Ssr1114被纯化，肽谱分析结果表明共纯化的的重组蛋白为H6-Ssr1114和Slr0664。【结论】ssr1114/slr0664 TA系统中抗毒素蛋白Ssr1114与毒素蛋白Slr0664之间存在相互作用。

Abstract:

Abstract: [Objective] We identified the interaction between toxin Slr0664 and antitoxin Slr1114, encoded by ssr1114/slr0664 system in the chromosome of cyanobacteria Synechocystis sp. PCC6803. [Methods] We constructed a recombinant plasmid in which only H6-Ssr1114 was induced to express, and another plasmid in which both H6-Ssr1114 and Slr0664 was co-expressed in E. coli Bl21(DE3). After induction, we used affinity capture technique to purify H6-Ssr1114 and copurified H6-Ssr1114 and Slr0664 under different conditions. We confirmed the co-purified H6-Ssr1114 and Slr0664 by using mass spectrographic analysis. [Results] When induced to express, Slr0664 showed cell toxicity leading to cell growth suppression or death. However, cells could grow normally if both H6-Ssr1114 and Slr0664 were induced to co-express. We could purify both H6-Ssr1114 and Slr0664 by His-Bind under native conditions, but only H6-Ssr1114 could be purified under denature conditions. The results of mass spectrometric analysis showed that the copurified proteins were H6-Ssr1114 and Slr0664. [Conclusion] The antitoxin Slr1114 and toxin Slr0664 in ssr1114/slr0664 TA system was interacted with each other.