Chains and heterogens:
PDB Chain Sequences:
>1bk7A (A:) fdsfwfvqqwppavcsfqksgscpgsglrtftihglwpqqsgtsltncpgspfditkish lqsqlntlwpnvlrannqqfwshewtkhgtcsestfnqaayfklavdmrnnydiigalrp haagpngrtksrqaikgflkakfgkfpglrcrtdpqtkvsylvqvvacfaqdgstlidct rdtcganfif