diff --git a/content/3.defense-systems/mok_hok_sok.md b/content/3.defense-systems/mok_hok_sok.md index 17683a2176fa013dc98ca58a9d422805e82726b1..a7bc48e602010cf139920842f9cbcdd000bd9cd1 100644 --- a/content/3.defense-systems/mok_hok_sok.md +++ b/content/3.defense-systems/mok_hok_sok.md @@ -10,9 +10,26 @@ tableColumns: Activator: Unknown Effector: Unknown PFAM: PF01848 +relevantAbstracts: + - doi: 10.1128/jb.178.7.2044-2050.1996 + - doi: 10.1016/0022-2836(92)90714-u +contributors: + - Jean Cury --- # Mok_Hok_Sok + +## Description + +The Mok Hok Sok system was discovered as a type 1 toxin-antitoxin system to stabilize plasmid R1 :ref{doi=10.1128/jb.161.1.292-298.1985}. Sok (Suppression of Killing) is an RNA and serves as the antitoxin. Hok (Host killing) is the toxin and Mok (Modulation of killing) is required for the expression of Hok :ref{doi=10.1016/j.mib.2007.03.003,10.1093/nar/gkl750}. +Hok/sok are not related to the T4 head protein Hoc and Soc. +This system defends against T4 phages only, as far as we currently know. + +## Molecular mechanism + +Upon infection of phage T4, the transcription is halted by the phage, which leads to a decreasing level of the antitoxin Sok within a few minutes. The Hok proteins manage to be process in their active form and trigger cell death by depolarization of the membrane :ref{doi=10.1006/jmbi.1995.0186} before the later stage of the phage infection (assembly, packaging and lysis). + + ## Example of genomic structure The Mok_Hok_Sok is composed of 2 proteins: Mok and Hok. @@ -51,7 +68,7 @@ graph LR; Pecota_1996[<a href='https://doi.org/10.1128/jb.178.7.2044-2050.1996'>Pecota and Wood, 1996</a>] --> Origin_0 Origin_0[R1 plasmid of Salmonella paratyphi <a href='https://ncbi.nlm.nih.gov/protein/WP_001372321.1'>WP_001372321.1</a>] --> Expressed_0[Escherichia coli] - Expressed_0[Escherichia coli] ----> T4 & LambdaVir + Expressed_0[Escherichia coli] ----> T4 subgraph Title1[Reference] Pecota_1996 end @@ -63,20 +80,10 @@ end end subgraph Title4[Phage infected] T4 - LambdaVir 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 </mermaid> -## Relevant abstracts - -::relevant-abstracts ---- -items: - - doi: 10.1128/jb.178.7.2044-2050.1996 - ---- -::