    New chain ID            Original chain ID

7bnm-pdb-bundle1.pdb:
           A                         A
           B                         B
           C                         C
           D                         D
           E                         N
           F                         R
           G                         T
           H                         V
           I                         Y
           J                         i
           K                         m
           L                         o
           M                         q
           N                         t
           O                         3
           P                         7
           Q                         9
           R                        BA
