    New chain ID            Original chain ID

9u7y-pdb-bundle1.pdb:
           A                        AA
           B                        AB
           C                        AC
           D                        AD
           E                        AE
           F                        BA
           G                        BB
           H                        BC
           I                        BD
           J                        BE
           K                        BF
           L                        BG
           M                        BH
           N                        BI
           O                        BJ
           P                        BK
           Q                        CA
           R                        CB
           S                        CC
           T                        CD
           U                        CE
           V                        CF
           W                        CG
           X                        CH
           Y                        CI
           Z                        CJ
           a                        CK
           b                        DA
           c                        DB
           d                        DC

9u7y-pdb-bundle2.pdb:
           A                        DD
           B                        DE
           C                        DF
           D                        DG
           E                        DH
           F                        DI
           G                        DJ
           H                        DK
           I                        EA
           J                        EB
           K                        EC
           L                        ED
           M                        EE
           N                        EF
           O                        EG
           P                        EH
           Q                        EI
           R                        EJ
           S                        EK
           T                        FA
           U                        FB
           V                        FC
           W                        FD
           X                        FE
           Y                        FF
           Z                        FG
           a                        FH
           b                        FI
           c                        FJ
           d                        FK
