ISG15-like
Contributors: Alba Herrero del Valle
ISG15-like (Interferon-stimulated gene 15 - like) systems (also known as Bil systems for Bacterial ISG15-like systems) are a 4-gene defense system comprising a homolog of ubiquitin-like ISG15 (BilA), ubiquitin-conjugating enzymes E1 (BilD) and E2 (BilB), and a deubiquitinase (BilC) (N/A, N/A) . It has been shown to defend against multiple coliphages (N/A) . The Bil system is analogous to the ISG15 system in humans, which protects against viruses.
Hör et al., have shown that the ISG15-like system defends bacteria against phages by impairing the infectivity of newly synthesized phages. It does so by preventing tail assembly that leads to non-infective tailless phages or by producing modified tails with an obstructed tail tip that are not capable of infecting. More specifically, BilA is conjugated to the central tail fiber (CTF) protein of the phage (N/A) .
The ISG15-like is composed of 4 proteins: BilA, BilB, BilC and BilD.
Here is an example found in the RefSeq database:
The ISG15-like system in Caulobacter segnis (GCF_023935105.1, NZ_CP096040) is composed of 4 proteins BilA (WP_252632187.1) BilB (WP_252632188.1) BilC (WP_252632189.1) BilD (WP_252632190.1)
Among the NaN complete genomes of RefSeq, the ISG15-like is detected in NaN genomes (NaN %). The system was detected in NaN different species.
Percent genome having the system
Minimum genomes count to display
graph LR;
Millman_2022[Millman et al., 2022] --> Origin_0
Origin_0[Collimonas sp. OK412
2609810443, 2609810442,
2609810441, 2609810440] --> Expressed_0[Escherichia coli]
Expressed_0[Escherichia coli] ----> T2 & T4 & T6 & T5 & SECphi4 & SECphi6 & SECphi18 & SECphi27 & T7 & SECphi17
Millman_2022[Millman et al., 2022] --> Origin_1
Origin_1[Caulobacter sp. Root343
2644236682, 2644236681,
2644236680, 2644236679] --> Expressed_1[Escherichia coli]
Expressed_1[Escherichia coli] ----> T4 & T6 & T5 & SECphi4 & SECphi6 & SECphi18 & SECphi27 & T7 & SECphi17
Millman_2022[Millman et al., 2022] --> Origin_2
Origin_2[Cupriavidus sp. SHE
2654619719, 2654619720,
2654619721, 2654619722] --> Expressed_2[Escherichia coli]
Expressed_2[Escherichia coli] ----> T2 & T4 & T6 & T5 & SECphi4 & SECphi6 & SECphi18 & SECphi27
Millman_2022[Millman et al., 2022] --> Origin_3
Origin_3[Paraburkholderia caffeinilytica
2843959492, 2843959493,
2843959494, 2843959495] --> Expressed_3[Escherichia coli]
Expressed_3[Escherichia coli] ----> T6 & SECphi27
Millman_2022[Millman et al., 2022] --> Origin_4
Origin_4[Thiomonas sp. FB-6
2523655165, 2523655166,
2523655167, 2523655168] --> Expressed_4[Escherichia coli]
Expressed_4[Escherichia coli] ----> SECphi27
subgraph Title1[Reference]
Millman_2022
end
subgraph Title2[System origin]
Origin_0
Origin_1
Origin_2
Origin_3
Origin_4
end
subgraph Title3[Expression species]
Expressed_0
Expressed_1
Expressed_2
Expressed_3
Expressed_4
end
subgraph Title4[Protects against]
T2
T4
T6
T5
SECphi4
SECphi6
SECphi18
SECphi27
T7
SECphi17
T4
T6
T5
SECphi4
SECphi6
SECphi18
SECphi27
T7
SECphi17
T2
T4
T6
T5
SECphi4
SECphi6
SECphi18
SECphi27
T6
SECphi27
SECphi27
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