    New chain ID            Original chain ID

7ycx-pdb-bundle1.pdb:
           A                         A
           B                         B
           D                         D
           E                         E
           F                         F
           G                         G
           H                         H
           I                         I
           K                         K
           M                         M
           P                         P
           Q                         Q
           U                         U
           1                         1
           2                         2
           3                         3
           4                         4
           5                         5
           6                         6
           7                         7
           8                         8
           9                         9
           a                         a
           b                         b
           c                         c
           d                         d

7ycx-pdb-bundle2.pdb:
           e                         e
           f                         f
           g                         g
           h                         h
           i                         i
           j                         j
           k                         k
           l                         l
