    New chain ID            Original chain ID

9gxg-pdb-bundle1.pdb:
           A                         A
           B                         B
           C                         C
           D                         D
           E                         E
           F                         F
           G                         G
           H                         H
           I                         I
           J                        AA
           K                        AB
           L                        AC
           M                        AD
           N                        AE
           O                        AF
           P                        AG
           Q                        AH
           R                        BA
           S                        BB
           T                        BC
           U                        BD
           V                        BE
           W                        BF
           X                        BG
           Y                        BH
           Z                        BI
           a                        CA
           b                        CB
           c                        CC
           d                        CD
           e                        CE
           f                        CF
           g                        CG
