Update psyrta.md

#267 (closed)

content/3.defense-systems/psyrta.md

@@ -10,9 +10,41 @@ tableColumns:
     Activator: Unknown
     Effector: Unknown
     PFAM: PF00270, PF00271, PF02481, PF04851, PF18306
+contributors:
+    - Ernest Mordret
+relevantAbstracts:
+    - doi: 10.1016/j.chom.2022.09.017
+    - doi: 10.1016/j.molcel.2013.02.002
+    - doi: 10.1371/journal.ppat.1005317
 ---
 
 # PsyrTA
+
+## Description
+
+Originally found in a high throughput shotgun cloning of bacterial fragments in E. coli looking for Toxin-Antitoxin pairs. PsyrTA is composed of two proteins, PsyrT, the toxin, is a RecQ family DNA helicase, and PsyrA, the antitoxin, was shown to be a Nucleotide-binding protein. Note that that system is sometimes called RqlHI :ref{doi=10.1371/journal.ppat.1005317}, where RqlH refers to PsyrT and RqlI to PsyrA
+
+## Molecular mechanisms
+
+from :ref{doi=10.1016/j.molcel.2013.02.002} :
+
+> The psyrT shares homology with domains of the RecQ helicase,
+> a family of proteins implicated in DNA repair (Bernstein et al.,
+> 2010); and the antitoxin of the same system, psyrA, has a nucle-
+> otide binding domain (COG0758) that was previously described
+> in proteins involved in DNA uptake
+
+
+from :ref{doi=10.1016/j.chom.2022.09.017} :
+
+> Both systems encode an antitoxin
+> with homology to DprA, a single-stranded DNA (ssDNA)-binding
+> protein known to be involved in DNA transformation (Mortier-
+> Barrière et al., 2007). The toxin contains a phosphoribosyl trans-
+> ferase (PRTase) domain, which was previously found in effectors
+> of retron abortive infection systems "
+
+
 ## Example of genomic structure
 
 The PsyrTA system is composed of 2 proteins: PsyrT and, PsyrA.
@@ -77,14 +109,5 @@ 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: 10.1016/j.chom.2022.09.017
-    - doi: 10.1016/j.molcel.2013.02.002
-
----
 ::