    New chain ID            Original chain ID

6pto-pdb-bundle1.pdb:
           X                         X
           Y                         Y
           Z                         Z
           n                         n
           o                         o
           p                         p
           q                         q
           e                         e
           h                         h
           i                         i
           j                         j
           k                         k
           l                         l
           m                         m
           A                         A
           B                         B
           C                         C
           D                         D
           E                         E
           2                         2
           3                         3
           4                         4
           5                         5
           6                         6
           7                         7
           a                         a
           b                         b
           c                         c
           d                         d

6pto-pdb-bundle2.pdb:
           r                         r
           F                         F
           G                         G
           H                         H
           I                         I
           J                         J
           K                         K
