    New chain ID            Original chain ID

5bkn-pdb-bundle1.pdb:
           A                         A
           B                         B
           C                         C
           D                         D
           E                         E
           F                         F
           G                         G
           H                         H
           I                         I
           J                         J
           K                         K
           L                         L
           M                         M
           N                         N
           O                         O
           P                         P
           Q                         S
           R                         T
           S                         V
           T                         X
           U                         Y
           V                         a
           W                         e
           X                         h
           Y                         i
           Z                         m
           a                         n
           b                        GG
           c                        HH
           d                        II
           e                        JJ
           f                        KK
           g                        TT
           h                        UU
           i                        WW
           j                        bb
           k                        kk
           l                        ll
           m                        qq
