    New chain ID            Original chain ID

7pbj-pdb-bundle1.pdb:
           A                        Ad
           B                        Ae
           C                        Af
           D                        Ak
           E                        Al
           F                        Am
           G                        Ar
           H                        As
           I                        At
           J                        Ay
           K                        Az
           L                        Ba
           M                        Bf
           N                        Bg
           O                        Bh
           P                        Bm
           Q                        Bn
           R                        Bo
           S                        Bt
           T                        Bu
           U                        Bv
