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title: Rst_TIR-NLR
layout: article
tableColumns:
    article:
      doi: 10.1016/j.chom.2022.02.018
      abstract: |
        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
contributors: 
  - Lucas Paoli
relevantAbstracts:
  - doi: 10.1016/j.chom.2022.02.018

Rst_TIR-NLR

Description

The Rst_TIR-NLR system is named after the first author of the paper describing it (Rousset et al. 2022) and the domains of the only protein it contains (TIR, toll-interleukin-1 receptor, and NLR, nucleotide-binding leucine rich repeat receptor) :ref{doi=10.1016/j.chom.2022.02.018}.

This system is very similar to other bacterial defense systems: bNACHT (https://defense-finder.pasteur.cloud/wiki/defense-systems/nlr), CARD_NLR (https://defense-finder.pasteur.cloud/wiki/defense-systems/card_nlr), Avs (AVAST) (https://defense-finder.pasteur.cloud/wiki/defense-systems/avs).

Molecular mechanisms

As far as we are aware, the molecular mechanism is unknown. However, the molecular mechanism of closely related systems was previously studied. See bNACHT (https://defense-finder.pasteur.cloud/wiki/defense-systems/nlr), CARD_NLR (https://defense-finder.pasteur.cloud/wiki/defense-systems/card_nlr) and Avs (AVAST) (https://defense-finder.pasteur.cloud/wiki/defense-systems/avs)

Example of genomic structure

The Rst_TIR-NLR is composed of 1 protein: TIR.

Here is an example found in the RefSeq database:

rst_tir-nlr

The Rst_TIR-NLR system in Methylosinus sp. C49 (GCF_009936375.1, NZ_AP022332) is composed of 1 protein: TIR (WP_161914415.1)

Distribution of the system among prokaryotes

Among the 22,803 complete genomes of RefSeq, the Rst_TIR-NLR is detected in 233 genomes (1.02 %).

The system was detected in 42 different species.

rst_tir-nlr

Proportion of genome encoding the Rst_TIR-NLR system for the 14 phyla with more than 50 genomes in the RefSeq database.

Structure

Rst_TIR-NLR

::molstar-pdbe-plugin

height: 700 dataUrl: /rst_tir-nlr/Rst_TIR-NLR__TIR-plddts_88.48123.pdb

::

Experimental validation

graph LR; Rousset_2022[Rousset et al., 2022] --> Origin_0 Origin_0[Klebsiella pneumoniae P4 loci WP_044784989.1] --> Expressed_0[Escherichia coli] Expressed_0[Escherichia coli] ----> T4 & P1 & CLB_P2 & LF82_P8 & AL505_P2 & T7 subgraph Title1[Reference] Rousset_2022 end subgraph Title2[System origin] Origin_0 end subgraph Title3[Expression species] Expressed_0 end subgraph Title4[Phage infected] T4 P1 CLB_P2 LF82_P8 AL505_P2 T7 end style Title1 fill:none,stroke:none,stroke-width:none style Title2 fill:none,stroke:none,stroke-width:none style Title3 fill:none,stroke:none,stroke-width:none style Title4 fill:none,stroke:none,stroke-width:none