Bacteria carry diverse genetic systems to defend against viral infection, some of which are found within prophages where they inhibit competing viruses. Phage satellites pose additional pressures on phages by hijacking key viral elements to their own benefit. Here, we show that E. coli P2-like phages and their parasitic P4-like satellites carry hotspots of genetic variation containing reservoirs of anti-phage systems. We validate the activity of diverse systems and describe PARIS, an abortive infection system triggered by a phage-encoded anti-restriction protein. Antiviral hotspots participate in inter-viral competition and shape dynamics between the bacterial host, P2-like phages, and P4-like satellites. Notably, the anti-phage activity of satellites can benefit the helper phage during competition with virulent phages, turning a parasitic relationship into a mutualistic one. Anti-phage hotspots are present across distant species and constitute a substantial source of systems that participate in the competition between mobile genetic elements.
Bacteria carry diverse genetic systems to defend against viral infection, some of which are found within prophages where they inhibit competing viruses. Phage satellites pose additional pressures on phages by hijacking key viral elements to their own benefit. Here, we show that E. coli P2-like phages and their parasitic P4-like satellites carry hotspots of genetic variation containing reservoirs of anti-phage systems. We validate the activity of diverse systems and describe PARIS, an abortive infection system triggered by a phage-encoded anti-restriction protein. Antiviral hotspots participate in inter-viral competition and shape dynamics between the bacterial host, P2-like phages, and P4-like satellites. Notably, the anti-phage activity of satellites can benefit the helper phage during competition with virulent phages, turning a parasitic relationship into a mutualistic one. Anti-phage hotspots are present across distant species and constitute a substantial source of systems that participate in the competition between mobile genetic elements.
Sensor:Unknown
Activator:Unknown
Effector:Unknown
PFAM:PF13676
PFAM:PF13676
contributors:
-Alba Herrero del Valle
relevantAbstracts:
-doi:10.1016/j.chom.2022.02.018
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# Rst_2TM_1TM_TIR
# Rst_2TM_1TM_TIR
## Description
The Rst_2TM_1TM_TIR system is carried by the P2-like phage AC1 and protects *Escherichia coli* C against lambda, LF82_P8 and P2 phages. This system is composed of three proteins, Rst_TIR_tm, that contains a TIR (Toll/interleukin-1 receptor) domain, Rst_1TM_TIR, that contains a transmembrane helix (TM) and Rst_2TM_TIR, that contains two TMs :ref{doi=10.1016/j.chom.2022.02.018}. Rousset et al. suggested that the TIR containing protein could generate a nucleotide messenger that in turn could activate the associated transmembrane proteins.
## Molecular mechanisms
As far as we are aware, the molecular mechanism is unknown.
## Example of genomic structure
## Example of genomic structure
The Rst_2TM_1TM_TIR is composed of 3 proteins: Rst_2TM_TIR, Rst_TIR_tm and Rst_1TM_TIR.
The Rst_2TM_1TM_TIR is composed of 3 proteins: Rst_2TM_TIR, Rst_TIR_tm and Rst_1TM_TIR.
