    New chain ID            Original chain ID

4v42-pdb-bundle1.pdb:
           A                        AA
           B                        AB
           C                        AC
           D                        AD
           E                        A1
           F                        AE
           G                        AF
           H                        AG
           I                        AH
           J                        AI
           K                        AJ
           L                        AK
           M                        AL
           N                        AM
           O                        AN
           P                        AO
           Q                        AP
           R                        AQ
           S                        AR
           T                        AS
           U                        AT
           V                        AU
           W                        AV
           X                        AW
           Y                        AX
           Z                        BA
           a                        BB
           b                        BC
           c                        BD
           d                        BE
           e                        BF
           f                        BG
           g                        BH
           h                        BI
           i                        BJ
           j                        BK
           k                        BL
           l                        BM
           m                        BN
           n                        BO
           o                        BP
           p                        BQ
           q                        BR
           r                        BS
           s                        BT
           t                        BU
           u                        BV
           v                        BW
           w                        BX
