add information on abip2

content/3.defense-systems/abip2.md

@@ -10,6 +10,8 @@ tableColumns:
     Activator: Unknown
     Effector: Unknown
     PFAM: PF00078
+contributors:
+  - Florian Tesson
 relevantAbstracts:
     - doi: 10.1023/A:1002027321171
     - doi: 10.1016/j.mib.2005.06.006
@@ -17,6 +19,25 @@ relevantAbstracts:
 ---
 
 # AbiP2
+
+## Description
+
+AbiP2 system was discovered in 2006 inside a variable region of the P2-like coliphages :ref{doi=10.1128/JB.188.4.1643-1647.2006}. This paper shows a relation with the known "Abi" system [AbiK](/defense-systems/abik).
+
+It was then proven to have an antiphage activity against T5 in E. coli :ref{doi=10.1126/science.aba0372}.
+
+AbiP2 is one of the so-called "Abi" systems for "Abortive infection" discovered in the 90's in research related to the dairy industry :ref{doi=10.1016/j.mib.2005.06.006}. AbiP2 is classified as possible abortive infection in :ref{doi=10.1016/j.mib.2023.102312}.
+
+This system is called AbiP2 for the P2-like phage and has no relation with AbiP (a homolog of [AbiC](/defense-systems/abic)](/defense-systems/abic)).
+
+However, with the discovery of dozens of new systems, it was categorized as one of the UG/Abi defense systems :ref{doi=10.1093/nar/gkac467} along with [DRT](/defense-systems/drt) different subsystems, [AbiA](/defense-systems/abia), [AbiK](/defense-systems/abik) and [Rst_RT_Nitralase_TM](/defense-systems/rst_rt-nitrilase-tm).
+
+Those systems are characterized by the presence of a reverse transcriptase domain of the "Unknown Group RT".
+
+## Molecular mechanism
+
+To our knowledge, the molecular mechanism is unknown. Similarly, for the other systems of this family, the molecular mechanism remains unknown.
+
 ## Example of genomic structure
 
 The AbiP2 is composed of 1 protein: AbiP2.