    New chain ID            Original chain ID

7pbw-pdb-bundle1.pdb:
           A                        AA
           B                        AB
           C                        AC
           D                        AD
           E                        AE
           F                        AF
           G                        AG
           H                        AH
           I                        AI
           J                        BA
           K                        BB
           L                        BC
           M                        BD
           N                        BE
           O                        BF
           P                        BG
           Q                        BH
           R                        BI
