NLR / bNACHT

Contributors: Héloïse Georjon

Description

This NLR like system is also known as the bNACHT systems.

Several proteins containing a NACHT module were found to have anti-phage activity. NACHT modules are also found in metazoans, where they play a role in innate immunity.

bNacht systems have some similarities with other defense systems: CARD_NLR , Rst_TIR-NLR, Avs.

Molecular mechanism

Bacterial NACHT module-containing proteins (bNACHT) encompass a C-terminal sensor, a central NACHT module, and N-terminal effector modules. The N-terminal effectors associated with bNACHT proteins are diverse, and include domains that have been previously described to be involved in other defense systems {doi=10.1016/j.cell.2023.04.015} As far as we are aware, the precise molecular mechanism of bNACHT is unknown.

Example of genomic structure

A total of 2 subsystems have been described for the NLR system.

Here is some examples found in the RefSeq database:

The NLR_like_bNACHT01 system in Colwellia sp. Arc7-D (GCF_003061515.1, NZ_CP028924) is composed of 1 protein: NLR_like_bNACHT01 (WP_162533747.1)

The NLR_like_bNACHT09 system in Parabacteroides johnsonii (GCF_020735865.1, NZ_CP085975) is composed of 1 protein: NLR_like_bNACHT09 (WP_009859882.1)

Distribution of the system among prokaryotes

Among the 22,803 complete genomes of RefSeq, the NLR is detected in 453 genomes (1.99 %).

The system was detected in 205 different species.

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

Structure

NLR_like_bNACHT01

Example 1

NLR_like_bNACHT09

Example 1

Experimental validation

      
graph LR;
    Kibby_2022[Kibby et al., 2022] --> Origin_0
    Origin_0[ bNACHT01
Klebsiella pneumoniae 
WP_015632533.1] --> Expressed_0[Escherichia coli]
    Expressed_0[Escherichia coli] ----> T4 & T5 & T6
    Kibby_2022[Kibby et al., 2022] --> Origin_1
    Origin_1[ bNACHT02
Escherichia coli 
WP_021557529.1] --> Expressed_1[Escherichia coli]
    Expressed_1[Escherichia coli] ----> T7 & MS2
    Kibby_2022[Kibby et al., 2022] --> Origin_2
    Origin_2[ bNACHT11
Klebsiella pneumoniae 
WP_114260439.1] --> Expressed_2[Escherichia coli]
    Expressed_2[Escherichia coli] ----> T2 & T4 & T6
    Kibby_2022[Kibby et al., 2022] --> Origin_3
    Origin_3[ bNACHT12
Escherichia coli 
WP_021519735.1] --> Expressed_3[Escherichia coli]
    Expressed_3[Escherichia coli] ----> T4 & T6 & MS2
    Kibby_2022[Kibby et al., 2022] --> Origin_4
    Origin_4[ bNACHT23
Escherichia coli 
WP_000433597.1] --> Expressed_4[Escherichia coli]
    Expressed_4[Escherichia coli] ----> T2 & T6 & T5
    Kibby_2022[Kibby et al., 2022] --> Origin_5
    Origin_5[ bNACHT25
Escherichia coli 
WP_001702659.1] --> Expressed_5[Escherichia coli]
    Expressed_5[Escherichia coli] ----> T2 & T4 & T6 & LambdaVir & MS2
    Kibby_2022[Kibby et al., 2022] --> Origin_6
    Origin_6[ bNACHT32
Escherichia coli 
WP_057688292] --> Expressed_6[Escherichia coli]
    Expressed_6[Escherichia coli] ----> T2 & T4 & T6 & LambdaVir & MS2
    Kibby_2022[Kibby et al., 2022] --> Origin_7
    Origin_7[ bNACHT67
Klebsiella michiganensis 
WP_064381242] --> Expressed_7[Escherichia coli]
    Expressed_7[Escherichia coli] ----> T2 & T4
    Kibby_2022[Kibby et al., 2022] --> Origin_8
    Origin_8[ bNACHT09
Escherichia coli 
WP_087866631] --> Expressed_8[Escherichia coli]
    Expressed_8[Escherichia coli] ----> T2 & T4 & T5 & LambdaVir & T3 & T7
    subgraph Title1[Reference]
        Kibby_2022
end
    subgraph Title2[System origin]
        Origin_0
        Origin_1
        Origin_2
        Origin_3
        Origin_4
        Origin_5
        Origin_6
        Origin_7
        Origin_8
end
    subgraph Title3[Expression species]
        Expressed_0
        Expressed_1
        Expressed_2
        Expressed_3
        Expressed_4
        Expressed_5
        Expressed_6
        Expressed_7
        Expressed_8
end
    subgraph Title4[Protects against]
        T4
        T5
        T6
        T7
        MS2
        T2
        T4
        T6
        T4
        T6
        MS2
        T2
        T6
        T5
        T2
        T4
        T6
        LambdaVir
        MS2
        T2
        T4
        T6
        LambdaVir
        MS2
        T2
        T4
        T2
        T4
        T5
        LambdaVir
        T3
        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

    

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