    New chain ID            Original chain ID

4v7a-pdb-bundle1.pdb:
           A                        AB
           B                        AC
           C                        AD
           D                        AE
           E                        AF
           F                        AG
           G                        AH
           H                        AI
           I                        AJ
           J                        AK
           K                        AL
           L                        AM
           M                        AN
           N                        AO
           O                        AP
           P                        AQ
           Q                        AR
           R                        AS
           S                        AT
           T                        AU
           U                        AA
           V                        A1
           W                        A2
           X                        BC
           Y                        BD
           Z                        BE
           a                        BF
           b                        BG
           c                        BH
           d                        BI
           e                        BJ
           f                        BK
           g                        BL
           h                        BM
           i                        BN
           j                        BO
           k                        BP
           l                        BQ
           m                        BR
           n                        BS
           o                        BT
           p                        BU
           q                        BV
           r                        BW
           s                        BX
           t                        BY
           u                        BZ
           v                        B0
           w                        B1
           x                        B2
           y                        B3
           z                        B4

4v7a-pdb-bundle2.pdb:
           A                        BA
           B                        BB
           C                        B5
