Bacteria encode sophisticated anti-phage systems that are diverse and versatile and display high genetic mobility. How this variability and mobility occurs remains largely unknown. Here, we demonstrate that a widespread family of pathogenicity islands, the phage-inducible chromosomal islands (PICIs), carry an impressive arsenal of defense mechanisms, which can be disseminated intra- and inter-generically by helper phages. These defense systems provide broad immunity, blocking not only phage reproduction, but also plasmid and non-cognate PICI transfer. Our results demonstrate that phages can mobilize PICI-encoded immunity systems to use them against other mobile genetic elements, which compete with the phages for the same bacterial hosts. Therefore, despite the cost, mobilization of PICIs may be beneficial for phages, PICIs, and bacteria in nature. Our results suggest that PICIs are important players controlling horizontal gene transfer and that PICIs and phages establish mutualistic interactions that drive bacterial ecology and evolution.
Bacteria encode sophisticated anti-phage systems that are diverse and versatile and display high genetic mobility. How this variability and mobility occurs remains largely unknown. Here, we demonstrate that a widespread family of pathogenicity islands, the phage-inducible chromosomal islands (PICIs), carry an impressive arsenal of defense mechanisms, which can be disseminated intra- and inter-generically by helper phages. These defense systems provide broad immunity, blocking not only phage reproduction, but also plasmid and non-cognate PICI transfer. Our results demonstrate that phages can mobilize PICI-encoded immunity systems to use them against other mobile genetic elements, which compete with the phages for the same bacterial hosts. Therefore, despite the cost, mobilization of PICIs may be beneficial for phages, PICIs, and bacteria in nature. Our results suggest that PICIs are important players controlling horizontal gene transfer and that PICIs and phages establish mutualistic interactions that drive bacterial ecology and evolution.
contributors:
-Florian Tesson
relevantAbstracts:
relevantAbstracts:
-doi:10.1016/j.cell.2022.07.014
-doi:10.1016/j.cell.2022.07.014
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# FS_GIY_YIG
# FS_GIY_YIG
## To do
## Description
FS_GIY_YIG or GIY_YIG system was discovered in 2022 :ref{doi=10.1016/j.cell.2022.07.014} inside the PICI KpCIXH209 in *Klebsiella pneumoniae*.
GIY_YIG is a single gene system that encodes for the GIY_YIG protein. The GIY_YIG protein contains the GIY YIG endonuclease domain.
## Molecular mechanism
As far as we are aware, the molecular mechanism is unknown. The endonuclease domain suggests a nucleic acid degrading mechanism.
