    New chain ID            Original chain ID

9o4r-pdb-bundle1.pdb:
           A                         A
           B                        AB
           C                         a
           D                        ab
           E                         B
           F                        BB
           G                         C
           H                        CB
           I                         D
           J                        DB
           K                         E
           L                        EB
           M                         F
           N                        FB
           O                         G
           P                        GB
           Q                         H
           R                        HB
           S                         I
           T                        IB
           U                         J
           V                        JB
           W                         K
           X                        KB
           Y                         L
           Z                        LB
           a                         M
           b                        MB
           c                         N
           d                        NB
           e                         O
           f                        OB
           g                         P
           h                        PB
           i                         Q
           j                        QB
           k                         R
           l                        RB
           m                         S
           n                        SB
           o                         T
           p                        TB
           q                         b
           r                        bb
           s                         c
           t                        cb
           u                         d
           v                        db
           w                         e
           x                        eb
           y                         f
           z                        fb
           0                         g
           1                        gb
           2                         h
           3                        hb
           4                         i
           5                        ib
           6                         j
           7                        jb
