    New chain ID            Original chain ID

6u2l-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                        AA
           R                        BB
           S                        CC
           T                        DD

6u2l-pdb-bundle2.pdb:
           A                        EE
           B                        FF
           C                        GG
           D                        HH
           E                        II
           F                        JJ
           G                        KK
           H                        LL
           I                        MM
           J                        NN
           K                        OO
           L                        PP
           M                         Q
           N                         R
           O                         S
           P                         T
           Q                         U
           R                         V
           S                         W
           T                         X
           U                         Y
           V                         Z
           W                         a
           X                         b
           Y                         c
           Z                         d
           a                         e
           b                         f
           c                         g
           d                         h
           e                         i
           f                         j
           g                         k
           h                         l
           i                         m
           j                         n
           k                         o
           l                         p
           m                         q
           n                         r
           o                         s
           p                         t
           q                         u
           r                         v
