[The interaction between chromosome-encoded toxin Slr0664 and antitoxin Slr1114 of cyanobacteria Synechocystis sp. PCC6803].
OBJECTIVE
We identified the interaction between toxin Slr0664 and antitoxin Slr1114, encoded by ssr114/ 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 B121(DE3). After induction, we used affinity capture technique to purify H,-Ssr1114 and copurified H6-Ssr1114 and Slr0664 under different conditions. We confirmed the co-purified H,-Ssrl 114 and S1l0664 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 H4-Ssr1114 could be purified under denature conditions. The results of mass spectrometric analysis showed that the copurified proteins were H,-Ssrlll4 and Slr0664.


CONCLUSIONS
The antitoxin Slr1114 and toxin Slr0664 in ssr1114/slr0664 TA system was interacted with each other.
Ye
Sen
S
Environmental School, Jiangsu University, Zhenjiang 212013, China. yesen1985828@yahoo.com.cn
Ning
Degang
D
D000992:Antitoxins / Q000032:analysis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001426:Bacterial Proteins / Q000032:analysis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001427:Bacterial Toxins / Q000032:analysis / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002876:Chromosomes, Bacterial / Q000235:genetics*; D011485:Protein Binding; D046939:Synechocystis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D000992:Antitoxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins