    New chain ID            Original chain ID

6mtb-pdb-bundle1.pdb:
           1                         1
           2                         2
           4                         4
           5                         5
           7                         7
           8                         8
           A                         A
           B                         B
           C                         C
           D                         D
           E                         E

6mtb-pdb-bundle2.pdb:
           A                         F
           B                         G
           C                         H
           D                         I
           E                         J
           F                         L
           G                         M
           H                         N
           I                         O
           J                         P
           K                         Q
           L                         R
           M                         S
           N                         T
           O                         U
           P                         V
           Q                         W
           R                         X
           S                         Y
           T                         Z
           U                         a
           V                         b
           W                         c
           X                         d
           Y                         e
           Z                         f
           a                         g
           b                         h
           c                         i
           d                         j
           e                         k
           f                         l
           g                         m
           h                         n
           i                         o
           j                         p
           k                         r
           l                         u
           m                         9
           n                        AA
           o                        BB
           p                        CC
           q                        DD
           r                        EE
           s                        FF
           t                        GG
           u                        HH
           v                        II
           w                        JJ
           x                        KK
           y                        LL
           z                        MM
           0                        NN

6mtb-pdb-bundle3.pdb:
           A                        OO
           B                        PP
           C                        QQ
           D                        RR
           E                        SS
           F                        TT
           G                        UU
           H                        VV
           I                        WW
           J                        XX
           K                        YY
           L                        ZZ
           M                        aa
           N                        bb
           O                        cc
           P                        dd
           Q                        ee
           R                        ff
           S                        gg
