    New chain ID            Original chain ID

9vgf-pdb-bundle1.pdb:
           A                        AX
           B                        AY
           C                        BX
           D                        BY
           E                        CX
           F                        CY
           G                        DX
           H                        DY
           I                        EX
           J                        EY
           K                        FX
           L                        FY
           M                        GX
           N                        GY
           O                        HX
           P                        HY
           Q                        IX
           R                        IY
           S                        JX
           T                        JY
           U                        KX
           V                        KY
           W                        LX
           X                        LY
           Y                        MX
           Z                        MY
           a                        NX
           b                        NY
           c                        OX
           d                        OY
           e                        PX
           f                        PY
           g                        QX
           h                        QY
