┌──────────── Escherichia coli DH1   
                                          ┌┴──────────── Escherichia coli 1044A (24)  
                                         ┌┴┬──────────── Escherichia coli E24377A (4)  
                                        ┌┤ └──────────── Escherichia coli B str. REL606 (3)  
                            ┌───────────┤└─ Escherichia coli K12 (45)  
    ┌───────────────────────┤           └──────────── Escherichia coli O55:H7 str. CB9615   
    │                       └┬─ Escherichia coli B7A (4)  
┌───┤                        └┬──────────── Escherichia coli O111:H- str. 11128   
│   │                         └──────────── Escherichia coli B354   
│   └┬──────────── Escherichia coli IAI39 (1)  
│    └┬──────────────────────────────────── Escherichia coli TA206   
│     └──────────────────────── Escherichia coli SMS-3-5   
┤                     ┌──────────── Escherichia coli 2362-75   
│                    ┌┴──────────── Escherichia coli M718   
│                   ┌┴─ Escherichia coli E2348/69 (1)  
│        ┌──────────┴───────────┬──────────────────────── Escherichia coli 042 (1)  
│       ┌┤                      └──────────── Escherichia coli MS 21-1   
│       │└───────────┬─────────────────────── Escherichia coli FVEC1302 (5)  
└───────┤            └──────────────────────┬──────────── Escherichia coli UM146   
        │                                   └─ Escherichia coli APEC O1 (5)  
        │┌──────────── Escherichia coli B185   
        └┤                                   ┌─ Escherichia coli 536 (4)  
         │┌──────────────────────────────────┴──────────────────────── Escherichia coli WV_060327   
         └┤                       ┌─ Escherichia coli NC101 (1)  
          │           ┌───────────┴──────────── Escherichia coli ED1a (1)  
          └───────────┤ ┌─────────────────────────────────── Escherichia coli 83972 (5)  
                      └┬┴──────────── Escherichia coli M605   
                       └┬──────────── Escherichia coli H299   
                        └─ Escherichia coli SE15   
  
Ribonucleotide reductase of class Ib (aerobic), beta subunit (EC 1.17.4.1) (29)