┌─ Escherichia coli (1-136/162) K12 (128)  
┌──────────────────────────────────────────────────────────────────┴─ Escherichia coli (1-126/152) O127:H6 str. E2348/69 (2)  
┤                                                                   ┌─ Escherichia coli 101-1 (23)  
└──────────────────────────────────────────────────────────────────┬┴─ Escherichia coli 53638 (2)  
                                                                   └┬─ Escherichia coli O157:H7 str. EC4024 (10)  
                                                                    └┬─ Escherichia coli K12 (96)  
                                                                     └┬─ Escherichia coli MS 185-1   
                                                                      └─ Escherichia coli (13-153/153) O157:H7 EDL933   
  

  
Nitrite-sensitive transcriptional repressor NsrR
 (6)
  
Iron-sulfur cluster regulator IscR
 (2)