کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6139577 | 1594239 | 2015 | 10 صفحه PDF | دانلود رایگان |
- The phage growth limitation (Pgl) system is a novel and elaborate mechanism of phage resistance.
- The system comprises, in part, a toxin/antitoxin system.
- The toxic protein, PglX, has DNA methyltransferase activity.
- The antitoxin is conferred by PglZ.
- Proteins with ATPase (PglY) and kinase (PglW) activities are also required for resistance.
The phage growth limitation system of Streptomyces coelicolor A3(2) is an unusual bacteriophage defence mechanism. Progeny ÏC31 phage from an initial infection are thought to be modified such that subsequent infections are attenuated in a Pgl+ host but normal in a Pglâ strain. Earlier work identified four genes required for phage resistance by Pgl. Here we demonstrate that Pgl is an elaborate and novel phage restriction system that, in part, comprises a toxin/antitoxin system where PglX, a DNA methyltransferase is toxic in the absence of a functional PglZ. In addition, the ATPase activity of PglY and a protein kinase activity in PglW are shown to be essential for phage resistance by Pgl. We conclude that on infection of a Pgl+ cell by bacteriophage ÏC31, PglW transduces a signal, probably via phosphorylation, to other Pgl proteins resulting in the activation of the DNA methyltransferase, PglX and this leads to phage restriction.
Journal: Virology - Volume 477, March 2015, Pages 100-109