Chains and heterogens:
PDB Chain Sequences:
>1b4kA (A:) msftpanraypytrlrrnrrddfsrrlvrenvltvddlilpvfvldgvnqresipsmpgv erlsidqllieaeewvalgipalalfpvtpvekksldaaeaynpegiaqratralrerfp elgiitdvaldpftthgqdgildddgyvlndvsidvlvrqalshaeagaqvvapsdmmdg rigairealesaghtnvrimaysakyasayygpfrdavgsasnlgkgnkatyqmdpansd ealhevaadlaegadmvmvkpgmpyldivrrvkdefraptfvyqvsgeyamhmgaiqngw laesvilesltafkragadgiltyfakqaaeqlrrgr
>1b4kA (A:) ypytrlrrnrrddfsrrlvrenvltvddlilpvfvldgvnqresipsmpgverlsidqll ieaeewvalgipalalfpvtpvekksldaaeaynpegiaqratralrerfpelgiitdva ldpftthgqdgildddgyvlndvsidvlvrqalshaeagaqvvapsdmmdgrigaireal esaghtnvrimaysakyasayygpfrdavgsasnlgkgnkatyqmdpansdealhevaad laegadmvmvkpgmpyldivrrvkdefraptfvyqvsgeyamhmgaiqngwlaesviles ltafkragadgiltyfakqaaeqlrr
>1b4kB (B:) msftpanraypytrlrrnrrddfsrrlvrenvltvddlilpvfvldgvnqresipsmpgv erlsidqllieaeewvalgipalalfpvtpvekksldaaeaynpegiaqratralrerfp elgiitdvaldpftthgqdgildddgyvlndvsidvlvrqalshaeagaqvvapsdmmdg rigairealesaghtnvrimaysakyasayygpfrdavgsasnlgkgnkatyqmdpansd ealhevaadlaegadmvmvkpgmpyldivrrvkdefraptfvyqvsgeyamhmgaiqngw laesvilesltafkragadgiltyfakqaaeqlrrgr
>1b4kB (B:) anraypytrlrrnrrddfsrrlvrenvltvddlilpvfvldgvnqresipsmpgverlsi dqllieaeewvalgipalalfpvtpvekksldaaeaynpegiaqratralrerfpelgii tdvaldpftthgqdgildddgyvlndvsidvlvrqalshaeagaqvvapsdmmdgrigai realesaghtnvrimaysakyasayygpfrdavgstyqmdpansdealhevaadlaegad mvmvkpgmpyldivrrvkdefraptfvyqvsgeyamhmgaiqngwlaesvilesltafkr agadgiltyfakqaaeqlrr