    New chain ID            Original chain ID

4nwr-pdb-bundle1.pdb:
           A                         A
           B                         B
           C                         D
           D                         F
           E                         H
           F                         J
           G                         L
           H                         N
           I                         P
           J                         R
           K                         T
           L                         V
           M                         X
           N                         Z
           O                         b
           P                         d
           Q                         f
           R                         h
           S                         j
           T                         l
           U                         n
           V                         p
           W                         r
           X                         t
           Y                         v
           Z                         x
           a                         z
           b                         1
           c                         3
           d                         5
           e                         7
           f                         9
           g                        AB
           h                        AD
           i                        AF
           j                        AH
           k                        AJ
           l                        AL
           m                        AN
           n                        AP
           o                        AR
           p                        AT
           q                        AV
           r                        AX
           s                        AZ
           t                        BB
           u                        BD
           v                        BF
           w                        BH
           x                         C
           y                         E
           z                         G
           0                         I
           1                         K
           2                         M
           3                         O
           4                         Q
           5                         S
           6                         U
           7                         W
           8                         Y
           9                         a

4nwr-pdb-bundle2.pdb:
           A                         c
           B                         e
           C                         g
           D                         i
           E                         k
           F                         m
           G                         o
           H                         q
           I                         s
           J                         u
           K                         w
           L                         y
           M                         0
           N                         2
           O                         4
           P                         6
           Q                         8
           R                        AA
           S                        AC
           T                        AE
           U                        AG
           V                        AI
           W                        AK
           X                        AM
           Y                        AO
           Z                        AQ
           a                        AS
           b                        AU
           c                        AW
           d                        AY
           e                        BA
           f                        BC
           g                        BE
           h                        BG
