    New chain ID            Original chain ID

8ibc-pdb-bundle1.pdb:
           A                        AA
           B                        AB
           C                        AC
           D                        AD
           E                        AE
           F                        AF
           G                        AG
           H                        AH
           I                        AI
           J                        AJ
           K                        AK
           L                        Aa
           M                        Ab
           N                        Ac
           O                        Ad
           P                        Ae
           Q                        Af
           R                        Ag
           S                        Ah
           T                        Aj
           U                        Ak
