Update pd-t4-4.md

content/3.defense-systems/pd-t4-4.md

@@ -10,7 +10,7 @@ tableColumns:
     Activator: Unknown
     Effector: Unknown
     PFAM: PF13175, PF13304
--contributors:
+contributors:
     - Nathalie Bechon
 relevantAbstracts
     - doi: 10.1038/s41564-022-01219-4
@@ -31,7 +31,7 @@ Here is an example found in the RefSeq database:
 
 ![pd-t4-4](/pd-t4-4/PD-T4-4.svg){max-width=750px}
 
-PD-T4-4 system in the genome of *Escherichia coli* (GCF_013376895.1) is composed of 2 proteins: PD-T4-4_B (WP_176670803.1)and, PD-T4-4_A (WP_027920142.1).
+PD-T4-4 system in the genome of *Escherichia coli* (GCF_013376895.1) is composed of 2 proteins: PD-T4-4_B (WP_176670803.1) and, PD-T4-4_A (WP_027920142.1).
 
 ## Distribution of the system among prokaryotes