Update mok_hok_sok.md

fix issue #188 (closed)

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 system is composed of 2 proteins: Mok and, Hok.
@@ -50,7 +67,7 @@ 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
@@ -62,20 +79,10 @@ 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
-
----
-::