    New chain ID            Original chain ID

9luu-pdb-bundle1.pdb:
           A                         B
           B                         C
           C                         D
           D                         E
           E                         F
           F                         G
           G                         H
           H                         I
           I                         J
           J                         L
           K                         M
           L                         b
           M                         c
           N                         d
           O                         e
           P                         f
           Q                         g
           R                         h
           S                         i
           T                         j
           U                         l
           V                         m
           W                         A
           X                        2a
           Y                        3a
           Z                        5a
           a                        6a
           b                         K
           c                         a
           d                        2b
           e                        3b
           f                        5b
           g                        6b
           h                         k
