    New chain ID            Original chain ID

7q4u-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                         Q
           R                         R
           S                         S
           T                         T
           U                         V
           V                         W
           W                         X
           X                         Y
           Y                         Z
           Z                        AA

7q4u-pdb-bundle2.pdb:
           A                        BA
           B                        CA
           C                        DA
           D                        EA
           E                        FA
           F                        GA
           G                        HA
           H                        IA
           I                        JA
           J                        KA
           K                        LA
           L                        MA
           M                        NA
           N                        OA
           O                        PA
           P                        QA
           Q                        RA
           R                        SA
           S                        TA
           T                        UA
           U                        VA
           V                        WA
