merge main and add information

content/3.defense-systems/pycsar.md

@@ -12,6 +12,7 @@ tableColumns:
     PFAM: PF00004, PF00027, PF00211, PF00899, PF01734, PF10137, PF14461, PF14464, PF18145, PF18153, PF18303, PF18967
 contributors: 
   - Lucas Paoli
+  - Florian Tesson
 relevantAbstracts:
   - doi: 10.1016/j.cell.2021.09.031
   - doi: 10.1038/s41586-022-04716-y
@@ -21,11 +22,15 @@ relevantAbstracts:
 
 ## Description
 
-The pyrimidine cyclase system for antiphage resistance (Pycsar) :ref{doi=10.1016/j.cell.2021.09.031}. In turn, phages encode anti-Pycsar (Apic) proteins encoded that counteract Pycsar defenses :ref{doi=10.1038/s41586-022-04716-y}
+The **py**rimidine **c**yclase **s**ystem for **a**ntiphage **r**esistance (Pycsar) :ref{doi=10.1016/j.cell.2021.09.031} is composed of at least two proteins: a cyclase and diverse effectors. The Pycsar defense system is related to the [CBASS](/defense-systems/cbass) but differs in the signaling molecule produced by the cyclase.
+
+In turn, phages encode anti-Pycsar (Apyc) proteins encoded that counteract Pycsar defenses :ref{doi=10.1038/s41586-022-04716-y}.
 
 ## Molecular mechanisms
 
-Pycsar uses cyclic nucleotide (pyrimidine cyclase) signals to induce cell death via Abi effectors activation and prevent viral propagation, while Apic degrade cyclic nucleotide signals to prevent host immune responses :ref{doi=10.1016/j.cell.2021.09.031,10.1038/s41586-022-04716-y}. 
+Pycsar uses cyclic nucleotide (pyrimidine cyclase, cCMP and cUMP) signals to induce cell death via diverse effectors activation and prevent viral propagation.
+
+While Apyc degrades cyclic nucleotide signals to prevent host immune responses :ref{doi=10.1016/j.cell.2021.09.031,10.1038/s41586-022-04716-y}. 
 
 ## Example of genomic structure