    New chain ID            Original chain ID

7pwx-pdb-bundle1.pdb:
           A                       HHH
           B                       III
           C                       JJJ
           D                       KKK
           E                       LLL
           F                       MMM
           G                       CCC
           H                       DDD
           I                       EEE
           J                       FFF
           K                       GGG
           L                       AAA
