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

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.