    New chain ID            Original chain ID

12ah-pdb-bundle1.pdb:
           B                         B
           D                         D
           M                         M
           N                         N
           W                         W
           X                         X
           e                         e
           q                         q
           F                         F
           H                         H
           P                         P
           Q                         Q
           T                         T
           Z                         Z
           a                         a
           b                         b
           f                         f
           g                         g
           h                         h
           i                         i
           j                         j
           k                         k
           l                         l
           m                         m
           n                         n
           o                         o
           p                         p
           r                         r
           s                         s
           t                         t
