Update pif.md according to Hackaton guidelines, see...

Update pif.md according to Hackaton guidelines, see #233 (closed)

content/3.defense-systems/pif.md

@@ -10,12 +10,28 @@ tableColumns:
     Activator: Unknown
     Effector: Membrane disrupting (?)
     PFAM: PF07693
+contributors: 
+  - Lucas Paoli
+relevantAbstracts:
+  - doi: 10.1007/BF00327934
+  - doi: 10.1016/j.virol.2004.06.001
+  - doi: 10.1128/jb.173.20.6507-6514.1991
+  - doi: 10.1038/newbio231037a0
 ---
 
 # Pif
+
+## Description
+
+The Pif system (Phage Inhibition by F factors) was first described by Morisson & Malamy :ref{doi=10.1038/newbio231037a0}. The Pif region of the F plasmid inhibits the phage T7 through abortive infection :ref{doi=10.1038/newbio231037a0,10.1007/BF00327934}.  
+
+## Molecular mechanisms
+
+PifA was later identified as the effector of the abortive infection :ref{doi=10.1128/jb.173.20.6507-6514.1991,10.1016/j.virol.2004.06.001} through nucleotide depletion by increased membrane permeability (also known as "leakage").
+
 ## Example of genomic structure
 
-The Pif system is composed of 2 proteins: PifC and, PifA.
+The Pif system is composed of 2 proteins: PifC and PifA.
 
 Here is an example found in the RefSeq database: 
 
@@ -75,15 +91,3 @@ end
     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: 10.1007/BF00327934
-    - doi: 10.1016/j.virol.2004.06.001
-    - doi: 10.1128/jb.173.20.6507-6514.1991
-
----
-::
-