Update wadjet.md

Add description, molecular mechanism and real structure #202 (closed)

content/3.defense-systems/wadjet.md

@@ -10,11 +10,27 @@ tableColumns:
     Activator: Direct
     Effector: Nucleic acid degrading
     PFAM: PF09660, PF09661, PF09664, PF09983, PF11795, PF11796, PF11855, PF13555, PF13558, PF13835
+contributors: 
+  - Florian Tesson
 relevantAbstracts:
     - doi: 10.1126/science.aar4120
+    - doi: 10.1016/j.molcel.2022.09.008
 ---
 
 # Wadjet
+
+## Description
+Wadjet is a defense system discovered in 2018 :ref{doi=10.1126/science.aar4120}. This system is named after the goddess [Wadjet](https://en.wikipedia.org/wiki/Wadjet) matron and protector of the lower Egypt.
+
+This system was discovered using the [defense island](/general-concepts/defense-islands) concept :ref{doi=10.1126/science.aar4120}. However, this system do not show any activity against phages, this system provides a resistance against plasmid transformation :ref{doi=10.1126/science.aar4120,10.1016/j.molcel.2022.09.008}.
+
+This system is composed of 4 genes: JetA, JetB, JetC and JetD. JetA, JetB and JetC were found to be similar to respectively MukF, MukE and MukB which are housekeeping genes :ref{doi=10.1126/science.aar4120,10.1098/rstb.2004.1606}. Notably, JetC (similar to MukB) is a SMC domain-containing protein. 
+
+### Molecular mechanism
+Wadjet was shown to possess an anti-plasmid activity via close, circular DNA cleavage :ref{doi=10.1098/rstb.2004.1606}. JetA, B and C were shown to form a complex which acts as a sensor detecting the foreign DNA using topology sensing. The JetD protein forms a homodimeric endonuclease that cleaves double-stranded DNA. JetD needs to be in contact with the JetABC complex to be able to cleave DNA.
+
+The precise mechanism suggested by the authors :ref{doi=10.1098/rstb.2004.1606} is that the JetABC complex binds to the DNA and extrudes DNA loops similarly to Muk and other SMC proteins :ref{doi=10.1126/science.abm4012,10.1126/science.abb0981}. These loops are then cleaved by JetD.
+
 ## Example of genomic structure
 
 A total of 3 subsystems have been described for the Wadjet system.
@@ -46,6 +62,21 @@ Proportion of genome encoding the Wadjet system for the 14 phyla with more than
 
 
 ## Structure
+
+### Experimentally determined structure
+
+From :ref{doi=10.1098/rstb.2004.1606}  in *Pseudomonas aeruginosa* PA14:
+
+::molstar-pdbe-plugin
+---
+height: 700
+dataUrls: 
+    - /wadjet/7til_JetD_2mer.pdb
+    - /wadjet/8dk1_JetABC_2_4_2mer_head.pdb
+    - /wadjet/8dk2_JetABC_2_4_2mer_dna.cif
+---
+::
+
 ### Wadjet_I
 ##### Example 1