    New chain ID            Original chain ID

7ogo-pdb-bundle1.pdb:
           A                       AAA
           B                       BBB
           C                       CCC
           D                       DDD
           E                       EEE
           F                       FFF
           G                       AaA
           H                       AeA
           I                       AhA
           J                       AkA
           K                       AnA
           L                       ArA
           M                       BaB
           N                       BcB
           O                       DaD
           P                       DeD
           Q                       DgD
           R                       DkD
           S                       DnD
           T                       DqD
           U                       EaE
           V                       EeE
