┬──────────────────────── Escherichia coli 2362-75 (28)  
└─────────────────────┬─ Escherichia coli K12 (99)  
                      └────────────────────────────────────────────── Escherichia coli B str. REL606 (3)  
  

  
Arginine pathway regulatory protein ArgR, repressor of arg regulon
 (3)