Chains and heterogens:
PDB Chain Sequences:
>1iwkA (A:) nlaplpphvpehlvfdfdmynpsnlsagvqeawavlqesnvpdlvwtrcngghwiatrgq lireayedyrhfssecpfipreageaydfiptsmdppeqrqfkalanqvvgmpvvdklen riqelacslieslrpqgqcnftedyaepfpirifmllaglpeediphlkyltdqmtrpdg smtfaeakealydylipiieqrrqkpgtdaisivangqvngrpitsdeakrmcglllvgg ldtvvnflsfsmeflakspehrqelierperipaaceellrrfslvadgriltsdyefhg vqlkkgdqillpqmlsglderenacpmhvdfsrqkvshttfghgshlclgqhlarreiiv tlkewltripdfsiapgaqiqhksgivsgvqalplvwdpattkav