Translational control and differential RNA decay are key elements regulating postsegregational expression of the killer protein encoded by the parB locus of plasmid R1 |
| |
Authors: | K Gerdes K Helin O W Christensen A L?bner-Olesen |
| |
Institution: | Department of Microbiology, Technical University of Denmark, Lyngby-Copenhagen. |
| |
Abstract: | The parB locus of plasmid R1, which mediates plasmid stability via postsegregational killing of plasmid-free cells, encodes two genes, hok and sok. The hok gene product is a potent cell-killing protein. The hok gene is regulated at the translational level by the sok gene-encoded repressor, a small anti-sense RNA complementary to the hok mRNA. The hok mRNA is extraordinarily stable, while the sok RNA decays rapidly. The mechanism of postsegregational killing is explained by the following model; the sok RNA molecule rapidly disappears in cells that have lost a parB-carrying plasmid, leading to translation of the stable hok mRNA. Consequently, the Hok protein is synthesized and killing of the plasmid-free cell follows. |
| |
Keywords: | |
|
|