    New chain ID            Original chain ID

9n7b-pdb-bundle1.pdb:
           A                        L1
           B                        L2
           C                        L3
           D                        L4
           E                        L5
           F                        L6
           G                        L7
           H                        L8
           I                        L9
           J                        LC
           K                        LD
           L                        LE
           M                        LF
           N                        LG
           O                        N2
           P                        NA
           Q                        NB
           R                        NF
           S                        NG
           T                        NL
           U                        NM
           V                        NP
           W                        NQ
           X                        NS
           Y                        NW
           Z                        SH
           a                        SI
           b                        SJ
           c                        SK
           d                        SL
           e                        SM
           f                        SR
           g                        SS
           h                        ST
           i                        SU
           j                        SW
           k                        SZ
