    New chain ID            Original chain ID

7pa6-pdb-bundle1.pdb:
           A                       KKK
           B                       LLL
           C                       MMM
           D                       NNN
           E                       OOO
           F                       PPP
           G                       QQQ
           H                       RRR
           I                       SSS
           J                       TTT
           K                       AAA
           L                       BBB
           M                       CCC
           N                       DDD
           O                       EEE
           P                       FFF
           Q                       GGG
           R                       HHH
           S                       III
           T                       JJJ
