    New chain ID            Original chain ID

7npn-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                        AL
           M                        AM
           N                        AN
           O                        AO
           P                        AP
           Q                        AQ
           R                        AR
           S                        AS
           T                        AT
           U                        AU
           V                        AV
           W                        AW
           X                        AX
           Y                        AY
           Z                        AZ
           a                        Aa
           b                        Ab
           c                        Ac
           d                        Ad
           e                        Ae
           f                        Af
           g                        Ag
           h                        Ah
           i                        Ai
           j                        Aj
           k                        Ak
           l                        Al
           m                        Am
           n                        An
           o                        Ao
           p                        Ap
           q                        Aq
           r                        Ar
           s                        As
           t                        At
           u                        Au
           v                        Av
           w                        Aw

7npn-pdb-bundle2.pdb:
           A                        Ax
           B                        Ay
           C                        Az
           D                        A0
           E                        A1
           F                        A2
           G                        A3
           H                        A4
           I                        A5
           J                        A6
           K                        A7
           L                        A8
           M                        A9
           N                        BA
           O                        BB
           P                        BC
           Q                        BD
           R                        BE
           S                        BF
           T                        BG
           U                        BH
           V                        BI
           W                        BJ
           X                        BK
           Y                        BL
           Z                        BM
           a                        BN
           b                        BO
           c                        BP
           d                        BQ
