    New chain ID            Original chain ID

6xir-pdb-bundle1.pdb:
           A                         A
           B                         B
           C                         C
           D                         D
           E                         E
           F                         F
           G                         G
           H                         H
           I                         I
           J                         J
           K                         L
           L                         M
           M                         N
           N                         O
           O                         P
           P                         Q
           Q                         R
           R                         S
           S                         T
           T                         U
           U                         V
           V                         W
           W                         X
           X                         Y
           Y                         Z
           Z                        AA
           a                        AB

6xir-pdb-bundle2.pdb:
           1                         1
           3                         3
           4                         4
           a                         a
           b                         b
           c                         c
           d                         d
           e                         e
           f                         f
           g                         g
           h                         h
           i                         i
           j                         j
           k                         k
           l                         l
           n                         n
           o                         o
           p                         p

6xir-pdb-bundle3.pdb:
           A                         2
           B                         q
           C                         r
           D                         s
           E                         t
           F                         u
           G                         v
           H                         w
           I                         x
           J                         y
           K                         z
           L                        AD
           M                        AE
           N                        AF
           O                        AG
           P                        AH
           Q                        AI
           R                        AJ
           S                        AK
           T                        AL
           U                        AM
           V                        AN
           W                        AO
           X                        AP
           Y                        AQ
           Z                        AR
           a                        AS
           b                        AT
           c                        AV
           d                        AX
           e                        AZ
